安卓 英文 外文文献翻译 Android API级别
物联网工程中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)Android: A Programmer’s Guide1 What Is Android1.1 Key Skills & Concepts● History of embedded device programming● Explanation of Open Handset Alliance● First look at the Android home screenIt can be said that, for a while, traditional desktop application developers have been spoiled. This is not to say that traditional desktop application development is easier than other forms of develop ment. However, as traditional desktop application developers, we have had the ability to create alm ost any kind of application we can imagine. I am including myself in this grouping because I got my start in desktop programming.One aspect that has made desktop programming more accessible is that we have had the ability to interact with the desktop operating system, and thus interact with any underlying hardware, pretty1freely (or at least with minimal exceptions). This kind of freedom to program independently, how ever, has never really been available to the small group of programmers who dared to venture int o the murky waters of cell phone development.NOTE ：I refer to two different kinds of developers in this discussion: traditional desktop applicati on developers, who work in almost any language and whose end product, applications, are built to run on any “desktop” operating system; and Android developers, J ava developers who develop for the Android platform. This is not for the purposes of saying one is by any means better or wors e than the other. Rather, the distinction is made for purposes of comparing the development styles and tools of desktop operating system environments to the mobile operating system environment1.2 Brief History of Embedded Device ProgrammingFor a long time, cell phone developers comprised a small sect of a slightly larger group of developers known as embedded device developers. Seen as a less “glamorous” sibling to desktop—and later web—development, embedded device development typically got the proverbial short end of the stick as far as hardware and operating system features, because embedded device manufacturers were notoriously stingy on feature support.Embedded device manufacturers typically needed to guard their hardware secrets closely, so they gave embedded device developers few libraries to call when trying to interact with a specific device. Embedded devices differ fro m desktops in that an embedded device is typically a “computer on a chip.” For example, consider your standard television remote control; it is not really seen as an overwhelming achievement of technological complexity. When any button is pressed, a chip interprets the signal in a way that has been programmed into the device. This allows the device to know what to expect from the input device (key pad), and how to respond to those commands (for example, turn on the television). This is a simple form of embedded device programming. However, believe it or not, simple devices such as these are definitely related to the roots of early cell phone devices and development.Most embedded devices ran (and in some cases still run) proprietary operating systems. The reason for choosing to create a proprietary operating system rather than use any consumer system was really a product of necessity. Simple devices did not need very robust and optimized operating systems.As a product of device evolution, many of the more complex embedded devices, such as early PDAs, household security systems, and GPSs, moved to somewhat standardized operating system platforms about five years ago. Small-footprint operating systems such as Linux, or even an embedded version of Microsoft Windows, have become more prevalent on many embedded devices. Around this time in device evolution, cell phones branched from other embedded devices onto their own path. This branching is evident whenyou examine their architecture.Nearly since their inception, cell phones have been fringe devices insofar as they run on proprietary software—software that is owned and controlled by the manufacturer, and is almost always considered to be a “closed” system. The practice of manufacturers using proprietary operating systems began more out of necessity than any other reason. That is, cell phone manufacturers typically used hardware that was completely developed in-house, or at least hardware that was specifically developed for the purposes of running cell phone equipment. As a result, there were no openly available, off-the-shelf software packages or solutions that would reliably interact with their hardware. Since the manufacturers also wanted to guard very closely their hardware trade secrets, some of which could be revealed by allowing access to the software level of the device, the common practice was, and in most cases still is, to use completely proprietary and closed software to run their devices. The downside to this is that anyone who wanted to develop applications for cell phones needed to have intimate knowledge of the proprietary environment within which it was to run. The solution was to purchase expensive development tools directly from the manufacturer. This isolated many of the “homebrew” develo pers.NOTE：A growing culture of homebrew developers has embraced cell phone application development. The term “homebrew” refers to the fact that these developers typically do not work for a cell phone development company and generally produce small, one-off products on their own time.Another, more compelling “necessity” that kept cell phone development out of the hands of theeveryday developer was the hardware manufacturers’ solution to the “memory versus need” dilemma. Until recently, cell phones did little more than execute and receive phone calls, track your contacts, and possiblysend and receive short text messages; not really the “Swiss army knives” of technology they are today.Even as late as 2002, cell phones with cameras were not commonly found in the hands of consumers.By 1997, small applications such as calculators and games (Tetris, for example) crept their way ontocell phones, but the overwhelming function was still that of a phone dialer itself. Cell phones had not yetbecome the multiuse, multifunction personal tools they are today. No one yet saw the need for Internetbrowsing, MP3 playing, or any of the multitudes of functions we are accustomed to using today. It ispossible that the cell phone manufacturers of 1997 did not fully perceive the need consumers would havefor an all-in-one device. However, even if the need was present, a lack of device memory and storagecapacity was an even bigger obstacle to overcome. More people may have wanted their devices to be all-in-one tools, but manufacturers still had to climb the memory hurdle.To put the problem simply, it takes memory to store and run applications on any device, cell phones included. Cell phones, as a device, until recently did not have the amount of memory available to them thatwould facilitate the inclusion of “extra” programs. Within the last two years, the price of memory hasreached very low levels. Device manufacturers now have the ability to include more memory at lowerprices. Many cell phones now have more standard memory than the average PC had in the mid-1990s. So,now that we have the need, and the memory, we can all jump in and develop cool applications for cellphones around the world, right? Not exactly.Device manufacturers still closely guard the operating systems that run on their devices. While a fewhave opened up to the point where they will allow some Java-based applications to run within a smallenvironment on the phone, many do not allow this. Even the systems that do allow some Java apps to rundo not allow the kind of access to the “core” system that standard desktop developers are accustomed to having.1.3 Open Handset Alliance and AndroidThis barrier to application development began to crumble in November of 2007 when Google, under theOpen Handset Alliance, released Android. The Open Handset Alliance is a group of hardware and softwaredevelopers, including Google, NTT DoCoMo, Sprint Nextel, and HTC, whose goal is to create a more opencell phone environment. The first product to be released under the alliance is the mobile device operatingsystem, Android.With the release of Android, Google made available a host of development tools and tutorials to aid would-be developers onto the new system. Help files, the platform software development kit (SDK), and even a developers’ community can be found at Google’s Android website, This site should be your starting point, and I highly encourage you to visit the site.NOTE ：Google, in promoting the new Android operating system, even went as far as to create a $10million contest looking for new and exciting Android applications.While cell phones running Linux, Windows, and even PalmOS are easy to find, as of this writing, nohardware platforms have been announced for Android to run on. HTC, LG Electronics, Motorola, andSamsung are members of the Open Handset Alliance, under which Android has been released, so we canonly hope that they have plans for a few Android-based devices in the near future. With its release inNovember 2007, the system itself is still in a software-only beta. This is good news for developers because it gives us a rare advance look at a future system and a chance to begin developing applications that willrun as soon as the hardware is released.NOTE：This strategy clearly gives the Open Handset Alliance a big advantage over other cell phone operating system developers, because there could be an uncountable number of applications available immediately for the first devices released to run Android.Introduction to AndroidAndroid, as a system, is a Java-based operating system that runs on the Linux 2.6 kernel. The system is very lightweight and full featured. Android applications are developed using Java and can be ported rather easily to the new platform. If you have not yet downloaded Java or are unsure about which version you need, I detail the installation of the development environment in Chapter 2. Other features of Android include an accelerated 3-D graphics engine (based on hardware support), database support powered by SQLite, and an integrated web browser.If you are familiar with Java programming or are an OOP developer of any sort, you are likely used to programmatic user interface (UI) development—that is, UI placement which is handled directly within the program code. Android, while recognizing and allowing for programmatic UI development, also supports the newer, XML-based UI layout. XML UI layout is a fairly new concept to the average desktop developer. I will cover both the XML UI layout and the programmatic UI development in the supporting chapters of this book.One of the more exciting and compelling features of Android is that, because of its architecture, third-partyapplications—including those that are “home grown”—are executed with the same system priority as those that are bundled with the core system. This is a major departure from most systems, which give embeddedsystem apps a greater execution priority than the thread priority available to apps created by third-partydevelopers. Also, each application is executed within its own thread using a very lightweight virtualmachine.Aside from the very generous SDK and the well-formed libraries that are available to us to develop with,the most exciting feature for Android developers is that we now have access to anything the operatingsystem has access to. In other words, if you want to create an application that dials the phone, you haveaccess to the phone’s dialer; if you want to create an application that utilizes the phone’s internal GPS (ifequipped), you have access to it. The potential for developers to create dynamic and intriguing applicationsis now wide open.On top of all the features that are available from the Android side of the equation, Google has thrown insome very tantalizing features of its own. Developers of Android applications will be able to tie their applications into existing Google offerings such as Google Maps and the omnipresent Google Search.Suppose you want to write an application that pulls up a Google map of where an incoming call isemanating from, or you want to be able to store common search results with your contacts; the doors ofpossibility have been flung wide open with Android.Chapter 2 begins your journey to Android development. You will learn the how’s and why’s of usingspecific development environments or integrated development environments (IDE), and you will downloadand install the Java IDE Eclipse.2 Application: Hello World2.1 Key Skills & Concepts● Creating new Android projects● Working with Views● Using a TextView● Modifying the main.xml file● Running applications on the Android EmulatorIn this chapter, you will be creating your first Android Activity. This chapter examines theapplication-building process from start to finish. I will show you how to create an Android project inEclipse, add code to the initial files, and run the finished application in the Android Emulator. The resultingapplication will be a fully functioning program running in an Android environment.Actually, as you move through this chapter, you will be creating more than one Android Activity.Computer programming tradition dictates that your first application be the typical Hello World! application,so in the first section you will create a standard Hello World! application with just a blank background andthe “Hello World!” text. Then, for the sake of enabling you to get to know the language better, the next section explains in detail the files automatically created by Android for your Hello World! application. You will create two iterations of this Activity, each using different techniques for displaying information to the screen. You will also create two different versions of a Hello World! application that will display an image that delivers the “Hello World!” message. This will give you a good introduction to the controls and inner workings of Android.NOTE：You will often see “application” and “Activity” used interchangeably. The difference between the two is that an application can be composed of multiple Activities, but one application must have at leastone Activity. Each “window” or screen of your application is a separate Activity. Therefore, if you create a fairly simple application with only one screen of data (like the Hello World! application in this chapter),that will be one Activity. In future chapters you will create applications with multiple Activities.To make sure that you get a good overall look at programming in Android, in Chapter 6 you will createboth of these applications in the Android SDK command-line environment for Microsoft Windows andLinux. In other words, this chapter covers the creation process in Eclipse, and Chapter 6 covers the creationprocess using the command-line tools. Therefore, before continuing, you should check that your Eclipseenvironment is correctly configured. Review the steps in Chapter 3 for setting the PATH statement for theAndroid SDK. You should also ensure that the JRE is correctly in your PATH statement.TIP：If you have configuration-related issues while attempting to work with any of the command-lineexamples, try referring to the configuration steps in Chapters 2 and 3; and look at the Android SDK documentation.2.2 Creating Your First Android Project in EclipseTo start your first Android project, open Eclipse. When you open Eclipse for the first time, it opens toan empty development environment (see Figure 5-1), which is where you want to begin. Your first task isto set up and name the workspace for your application. Choose File | New | Android Project, which willlaunch the New Android Project wizard.CAUTION Do not select Java Project from the New menu. While Android applications are written in Java, and you are doing all of your development in Java projects, this option will create a standard Java application. Selecting Android Project enables you to create Android-specific applications.If you do not see the option for Android Project, this indicates that the Android plugin for Eclipse was not fully or correctly installed. Review the procedure in Chapter 3 for installing the Android plugin for Eclipse to correct this.2.3 The New Android Project wizard creates two things for youA shell application that ties into the Android SDK, using the android.jar file, and ties the project intothe Android Emulator. This allows you to code using all of the Android libraries and packages, and alsolets you debug your applications in the proper environment.Your first shell files for the new project. These shell files contain some of the vital application blocksupon which you will be building your programs. In much the same way as creating a Microsoft .NETapplication in Visual Studio generates some Windows-created program code in your files, using the Android Project wizard in Eclipse generates your initial program files and some Android-created code. Inaddition, the New Android Project wizard contains a few options, shown next, that you must set to initiate your Android project. For the Project Name field, for purposes of this example, use the titleHelloWorldText. This name sufficiently distinguishes this Hello World! project from the others that youwill be creating in this chapter.In the Contents area, keep the default selections: the Create New Project inWorkspace radio button should be selected and the Use Default Location check box should be checked.This will allow Eclipse to create your project in your default workspace directory. The advantage ofkeeping the default options is that your projects are kept in a central location, which makes ordering,managing, and finding these projects quite easy. For example, if you are working in a Unix-basedenvironment, this path points to your $HOME directory.If you are working in a Microsoft Windows environment, the workspace path will beC:/Users/<username>/workspace, as shown in the previous illustration. However, for any number of reasons, you may want to uncheck the Use Default Location check box and select a different location for your project. One reason you may want to specify a different location here is simply if you want to choose a location for this specific project that is separate from other Android projects. For example, you may want to keep the projects that you create in this book in a different location from projects that you create in the future on your own. If so, simply override the Location option to specify your own custom location directory for this project.3 Application FundamentalsAndroid applications are written in the Java programming language. The compiled Java code — along with any data and resource files required by the application — is bundled by the aapt tool into an Androidpackage, an archive file marked by an .apk suffix. This file is the vehicle for distributing the application and installing it on mobile devices; it's the file users download to their devices. All the code in a single .apk file is considered to be one application.In many ways, each Android application lives in its own world:1. By default, every application runs in its own Linux process. Android starts the process when any of the application's code needs to be executed, and shuts down the process when it's no longer needed and system resources are required by other applications.2. Each process has its own virtual machine (VM), so application code runs in isolation from the code of all other applications.3. By default, each application is assigned a unique Linux user ID. Permissions are set so that the application's files are visible only to that user and only to the application itself — although there are ways to export them to other applications as well.It's possible to arrange for two applications to share the same user ID, in which case they will be able to see each other's files. To conserve system resources, applications with the same ID can also arrange to run in the same Linux process, sharing the same VM.3.1 Application ComponentsA central feature of Android is that one application can make use of elements of other applications (provided those applications permit it). For example, if your application needs to display a scrolling list of images and another application has developed a suitable scroller and made it available to others, you can call upon that scroller to do the work, rather than develop your own. Application have four types of components:(1)ActivitiesAn activity presents a visual user interface for one focused endeavor the user can undertake. For example, an activity might present a list of menu items users can choose from or it might display photographs along with their captions. A text messaging application might have one activity that shows a list of contacts to send messages to, a second activity to write the message to the chosen contact, and other activities to review old messages or change settings. Though they work together to form a cohesive user interface, each activity is independent of the others. Each one is implemented as a subclass of the Activity base class.An application might consist of just one activity or, like the text messaging application just mentioned, it may contain several. What the activities are, and how many there are depends, of course, on the application and its design. Typically, one of the activities is marked as the first one that should be presented to the user when the application is launched. Moving from one activity to another is accomplished by having the current activity start the next one.Each activity is given a default window to draw in. Typically, the window fills the screen, but it might be smaller than the screen and float on top of other windows. An activity can also make use of additional windows —— for example, a pop-up dialog that calls for a user response in the midst of the activity, or a windowswindow that presents users with vital information when they select a particular item on-screen.The visual content of the window is provided by a hierarchy of views — objects derived from the base View class. Each view controls a particular rectangular space within the window. Parent views contain and organize the layout of their children. Leaf views (those at the bottom of the hierarchy) draw in the rectangles they control and respond to user actions directed at that space. Thus, views are where the activity's interaction with the user takes place.For example, a view might display a small image and initiate an action when the user taps that image. Android has a number of ready-made views that you can use — including buttons, text fields, scroll bars, menu items, check boxes, and more.A view hierarchy is placed within an activity's window by the Activity.setContentView() method. The content view is the View object at the root of the hierarchy. (See the separate User Interface document for more information on views and the hierarchy.)(2)ServicesA service doesn't have a visual user interface, but rather runs in the background for an indefinite period of time. For example, a service might play background music as the user attends to other matters, or it might fetch data over the network or calculate something and provide the result to activities that need it. Each service extends the Service base class.A prime example is a media player playing songs from a play list. The player application would probably have one or more activities that allow the user to choose songs and start playing them. However, the musicplayback itself would not be handled by an activity because users will expect the music to keep playing even after they leave the player and begin something different. To keep the music going, the media player activity could start a service to run in the background. The system would then keep the music playback service running even after the activity that started it leaves the screen.It's possible to connect to (bind to) an ongoing service (and start the service if it's not already running). While connected, you can communicate with the service through an interface that the service exposes. For the music service, this interface might allow users to pause, rewind, stop, and restart the playback.Like activities and the other components, services run in the main thread of the application process. So that they won't block other components or the user interface, they often spawn another thread for time-consuming tasks (like music playback). See Processes and Threads, later.(3)Broadcast receiversA broadcast receiver is a component that does nothing but receive and react to broadcast announcements. Many broadcasts originate in system code — for example, announcements that the timezone has changed, that the battery is low, that a picture has been taken, or that the user changed a language preference. Applications can also initiate broadcasts — for example, to let other applications know that some data has been downloaded to the device and is available for them to use.An application can have any number of broadcast receivers to respond to any announcements it considers important. All receivers extend the BroadcastReceiver base class.Broadcast receivers do not display a user interface. However, they may start an activity in response to the information they receive, or they may use the NotificationManager to alert the user. Notifications can get the user's attention in various ways —— flashing the backlight, vibrating the device, playing a sound, and so the user's attention in various wayson. They typically place a persistent icon in the status bar, which users can open to get the message.(4)Content providersA content provider makes a specific set of the application's data available to other applications. The data can be stored in the file system, in an SQLite database, or in any other manner that makes sense. The content provider extends the ContentProvider base class to implement a standard set of methods that enable other applications to retrieve and store data of the type it controls. However, applications do not call these methods directly. Rather they use a ContentResolver object and call its methods instead. A ContentResolver can talk to any content provider; it cooperates with the provider to manage any interprocess communication that's involved.See the separate Content Providers document for more information on using content providers. Whenever there's a request that should be handled by a particular component, Android makes sure that the application process of the component is running, starting it if necessary, and that an appropriate instance of the component is available, creating the instance if necessary.3.2 Activating components: intentsContent providers are activated when they're targeted by a request from a ContentResolver. The other three components — activities, services, and broadcast receivers — are activated by asynchronous messages called intents. An intent is an Intent object that holds the content of the message. For activities and services, it names the action being requested and specifies the URI of the data to act on, among other things. For example, it might convey a request for an activity to present an image to the user or let the user edit some text. For broadcast receivers, theIntent object names the action being announced. For example, it might announce to interested parties that the camera button has been pressed.。
android的多国语言适配
android多国语言文件夹android多国语言文件夹文件汇总如下：（有些语言的书写顺序可能跟中文是相反的）中文（中国）：values-zh-rCN中文（台湾）：values-zh-rTW中文（香港）：values-zh-rHK英语（美国）：values-en-rUS英语（英国）：values-en-rGB英文（澳大利亚）：values-en-rAU英文（加拿大）：values-en-rCA英文（爱尔兰）：values-en-rIE英文（印度）：values-en-rIN英文（新西兰）：values-en-rNZ英文（新加坡）：values-en-rSG英文（南非）：values-en-rZA阿拉伯文（埃及）：values-ar-rEG阿拉伯文（以色列）：values-ar-rIL保加利亚文: values-bg-rBG加泰罗尼亚文：values-ca-rES捷克文：values-cs-rCZ丹麦文：values-da-rDK德文（奥地利）：values-de-rAT德文（瑞士）：values-de-rCH德文（德国）：values-de-rDE德文（列支敦士登）：values-de-rLI希腊文：values-el-rGR西班牙文（西班牙）：values-es-rES西班牙文（美国）：values-es-rUS芬兰文（芬兰）：values-fi-rFI法文（比利时）：values-fr-rBE法文（加拿大）：values-fr-rCA法文（瑞士）：values-fr-rCH法文（法国）：values-fr-rFR希伯来文：values-iw-rIL印地文：values-hi-rIN克罗里亚文：values-hr-rHR匈牙利文：values-hu-rHU印度尼西亚文：values-in-rID意大利文（瑞士）：values-it-rCH意大利文（意大利）：values-it-rIT 日文：values-ja-rJP韩文：values-ko-rKR立陶宛文：valueslt-rLT拉脱维亚文：values-lv-rLV挪威博克马尔文：values-nb-rNO 荷兰文(比利时)：values-nl-BE荷兰文（荷兰）：values-nl-rNL波兰文：values-pl-rPL葡萄牙文（巴西）：values-pt-rBR 葡萄牙文（葡萄牙）：values-pt-rPT 罗马尼亚文：values-ro-rRO俄文：values-ru-rRU斯洛伐克文：values-sk-rSK斯洛文尼亚文：values-sl-rSI塞尔维亚文：values-sr-rRS 瑞典文：values-sv-rSE泰文：values-th-rTH塔加洛语：values-tl-rPH土耳其文：values--r-rTR乌克兰文：values-uk-rUA 越南文：values-vi-rVN。
Android—API中文文档
Android2.2——API中文文档LLGYZB@目录：（1）—— TextView（2）—— EditText（3）—— AccessibilityService（4）—— Manifest（5）—— View（6）—— ImageView（7）—— ImageButton（8）—— QuickContactBadge（9）—— ZoomButton（10）—— CheckBox（11）—— RadioButton（12）—— Button（13）—— ToggleButton（14）—— ViewStub（15）——GridView一、TextView1、结构ng.Object↳android.view.View↳android.widget.TextView2、已知直接子类：Button, CheckedTextView, Chronometer, DigitalClock, EditText3、已知间接子类：AutoCompleteTextView, CheckBox, CompoundButton, ExtractEditText,MultiAutoCompleteTextView, RadioButton, ToggleButton二、EditText1、结构ng.Object↳ android.view.View↳android.widget.TextView↳ android.widget.EditText已知直接子类：AutoCompleteTextView, ExtractEditText已知间接子类： MultiAutoCompleteTextView2、xml 属性补充说明：a).由于是继承自TextView，所以属性是一样的，但是这里重点补充了输入法相关的属性说明和研究，部分注释也做了相应的调整。
b).Word格式下载/source/26641643、例子3.1<!--[endif]-->android:imeOptions例子<EditText android:id="@+id/txtTest" android:imeOptions="actionGo" android:layout_width="100dp" android:layout_height="wrap_con tent"></EditText>((EditText)findViewById(R.id.txtTest)).setOnEditorActionListener( new TextView.OnEditorActionListener() {@Overridepublic boolean onEditorAction(TextView v, int actionI d,KeyEvent event) {if (actionId == EditorInfo.IME_ACTION_GO) {Toast.makeText(TestActivity.this, "你点了Go!", Toast.LENGTH_SHORT).show();}return false;}});三、AccessibilityService1、结构ng.Object↳android.content.Context↳android.content.ContextWrapper↳android.app.Service↳android.accessibilityservice.AccessibilityServicepublic abstract class AccessibilityService extends Service2、类概述当AccessibilityEvent事件被启动后AccessibilityService 会接收回调函数运行于后台，这些事件指的是在用户接口间的状态转换，比如,焦点变化，按钮被点击等。
安卓应用基础中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)Android Application FundamentalsAndroid applications are written in the Java programming language. The Android SDK tools compile the code—along with any data and resource files—into an Android package, an archive file with an .apk suffix. All the code in a single .apk file is considered to be one application and is the file that Android-powered devices use to install the application.Once installed on a device, each Android application lives in its own security sandbox:The Android operating system is a multi-user Linux system in which each application is a different user.By default, the system assigns each application a unique Linux user ID (the ID is used only by the system and is unknown to the application). The system sets permissions for all the files in an application so that only the user ID assigned to that application can access them.Each process has its own virtual machine (VM), so an application's code runs in isolation from other applications.By default, every application runs in its own Linux process. Android starts the process when any of the application's components need to be executed, then shuts down the process when it's no longer needed or when the system must recover memory for other applications. In this way, the Android system implements the principle of least privilege. That is, each application, by default, has access only to the components that it requires to do its work and no more. This creates a very secure environment in which an application cannot access parts of the system for which it is not given permission.However, there are ways for an application to share data with other applications and for an application to access system services:It's possible to arrange for two applications to share the same Linux user ID, in which case they are able to access each other's files. To conserve system resources, applications with the same user ID can also arrange to run in the same Linux process and share the same VM (the applications must also be signed with the same certificate).An application can request permission to access device data such as the user's contacts, SMS messages, the mountable storage (SD card), camera, Bluetooth, and more. All application permissions must be granted by the user at install time.That covers the basics regarding how an Android application exists within the system. The rest of this document introduces you to:1、The core framework components that define your application.2、The manifest file in which you declare components and required device features for your application.3、Resources that are separate from the application code and allow your application to gracefully optimize its behavior for a variety of device configurations.Application ComponentsApplication components are the essential building blocks of an Android application. Each component is a different point through which the system can enter your application. Not all components are actual entry points for the user and some depend on each other, but each oneexists as its own entity and plays a specific role—each one is a unique building block that helps define your application's overall behavior.There are four different types of application components. Each type serves a distinct purpose and has a distinct lifecycle that defines how the component is created and destroyed.Here are the four types of application components:ActivitiesAn activity represents a single screen with a user interface. For example, an email application might have one activity that shows a list of new emails, another activity to compose an email, and another activity for reading emails. Although the activities work together to form a cohesive user experience in the email application, each one is independent of the others. As such, a different application can start any one of these activities (if the email application allows it). For example, a camera application can start the activity in the email application that composes new mail, in order for the user to share a picture.An activity is implemented as a subclass of Activity and you can learn more about it in the Activities developer guide.ServicesA service is a component that runs in the background to perform long-running operations or to perform work for remote processes. A service does not provide a user interface. For example, a service might play music in the background while the user is in a different application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to it in order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database, on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or evenmodify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such as ContactsContract.Data) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.A broadcast receiver is implemented as a subclass of BroadcastReceiver and each broadcast is delivered as an Intent object. For more information, see the BroadcastReceiver class.A unique aspect of the Android system design is that any application can start another application’s component. For example, if you want the user to capture a photo with the device camera, there's probably another application that does that and your application can use it, instead of developing an activity to capture a photo yourself. You don't need to incorporate or even link to the code from the camera application. Instead, you can simply start the activity in the camera application that captures a photo. When complete, the photo is even returned to your application so you can use it. To the user, it seems as if the camera is actually a part of your application.When the system starts a component, it starts the process for that application (if it's not already running) and instantiates the classes needed for the component. For example, if your application starts the activity in the camera application that captures a photo, that activity runs in the process that belongs to the camera application, not in your application's process. Therefore, unlike applications on most other systems, Android applications don't have a single entry point (there's no main()function, for example).Because the system runs each application in a separate process with file permissions that restrict access to other applications, your application cannot directly activate a component from another application. The Android system, however, can. So, to activate a component in another application, you must deliver a message to the system that specifies your intent to start a particular component. The system then activates the component for you.Activating ComponentsThree of the four component types—activities, services, and broadcast receivers—are activated by an asynchronous message called an intent. Intents bind individual components to each other at runtime (you can think of them as the messengers that request an action from other components), whether the component belongs to your application or another.An intent is created with an Intent object, which defines a message to activate either a specific component or a specific type of component—an intent can be either explicit or implicit, respectively.For activities and services, an intent defines the action to perform (for example, to "view" or "send" something) and may specify the URI of the data to act on (among other things that the component being started might need to know). For example, an intent might convey a request for an activity to show an image or to open a web page. In some cases, you can start an activity to receive a result, in which case, the activity also returns the result in an Intent (for example, you can issue an intent to let the user pick a personal contact and have it returned to you—the return intent includes a URI pointing to the chosen contact).For broadcast receivers, the intent simply defines the announcement being broadcast (for example, a broadcast to indicate the device battery is low includes only a known action string that indicates "battery is low").The other component type, content provider, is not activated by intents. Rather, it is activated when targeted by a request from a ContentResolver. T he content resolver handles all direct transactions with the content provider so that the component that's performing transactions with the provider doesn't need to and instead calls methods onthe ContentResolver object. This leaves a layer of abstraction between the content provider and the component requesting information (for security).There are separate methods for activating each type of component:You can start an activity (or give it something new to do) by passingan Intent to startActivity() or startActivityForResult() (when you want the activity to return a result).You can start a service (or give new instructions to an ongoing service) by passingan Intent to startService(). Or you can bind to the service by passing an Intent to bindService().You can initiate a broadcast by passing an Intent to methodslike sendBroadcast(), sendOrderedBroadcast(), or sendStickyBroadcast().You can perform a query to a content provider by calling query() on a ContentResolver.For more information about using intents, see the Intents and Intent Filters document. More information about activating specific components is also provided in the following documents: Activities, Services, BroadcastReceiver and Content Providers.Declaring componentsThe primary task of the manifest is to inform the system about the application's components. For example, a manifest file can declare an activity as follows:In the <application> element, the android:icon attribute points to resources for an icon that identifies the application.In the <activity> element, the android:name at tribute specifies the fu lly qualified class name of the Activity subclass and the android:label attributes specifies a string to use as the user-visible label for the activity.You must declare all application components this way:1、<activity>elements for activities2、<service> elements for services3、<receiver>elements for broadcast receivers4、<provider>elements for content providersActivities, services, and content providers that you include in your source but do not declare in the manifest are not visible to the system and, consequently, can never run. However, broadcast receivers can be either declared in the manifest or created dynamically in code (as BroadcastReceiver objects) and registered with the system bycalling registerReceiver().Declaring component capabilitiesAs discussed above, in Activating Components, you can use an Intent to start activities, services, and broadcast receivers. You can do so by explicitly naming the target component (using the component class name) in the intent. However, the real power of intents lies in the concept of intent actions. With intent actions, you simply describe the type of action you want to perform (and optionally, the data upon which you’d like to perform the action) and allow the system to find a component on the device that can perform the action and start it. If there are multiple components that can perform the action described by the intent, then the user selects which one to use.The way the system identifies the components that can respond to an intent is by comparing the intent received to the intent filters provided in the manifest file of other applications on the device.When you declare a component in your application's manifest, you can optionally include intent filters that declare the capabilities of the component so it can respond to intents from other applications. You can declare an intent filter for your component by addingan <intent-filter>element as a child of the component's declaration element.For example, an email application with an activity for composing a new email might declare an intent filter in its manifest entry to respond to "send" intents (in order to send email). An activity in your application can then create an intent with the “send” action (ACTION_SEND), which the system matches to the email application’s “send” activity and launches it when you invoke the intent with startActivity().For more about creating intent filters, see the Intents and Intent Filters document.Declaring application requirementsThere are a variety of devices powered by Android and not all of them provide the same features and capabilities. In order to prevent your application from being installed on devices that lack features needed by your application, it's important that you clearly define a profile for the types of devices your application supports by declaring device and software requirements in your manifest file. Most of these declarations are informational only and the system does not read them, but external services such as Google Play do read them in order to provide filtering for users when they search for applications from their device.For example, if your application requires a camera and uses APIs introduced in Android 2.1 (API Level7), you should declare these as requirements in your manifest file. That way, devices that do not have a camera and have an Android version lower than 2.1 cannot install your application from Google Play.However, you can also declare that your application uses the camera, but doesnot require it. In that case, your application must perform a check at runtime to determine if the device has a camera and disable any features that use the camera if one is not available.Here are some of the important device characteristics that you should consider as you design and develop your application:Screen size and densityIn order to categorize devices by their screen type, Android defines two characteristics for each device: screen size (the physical dimensions of the screen) and screen density (the physical density of the pixels on the screen, or dpi—dots per inch). To simplify all the different types of screen configurations, the Android system generalizes them into select groups that make them easier to target.The screen sizes are: small, normal, large, and extra large.The screen densities are: low density, medium density, high density, and extra high density.By default, your application is compatible with all screen sizes and densities, because the Android system makes the appropriate adjustments to your UI layout and image resources. However, you should create specialized layouts for certain screen sizes and provide specialized images for certain densities, using alternative layout resources, and by declaring in your manifest exactly which screen sizes your application supports withthe <supports-screens> element.For more information, see the Supporting Multiple Screens document.Input configurationsMany devices provide a different type of user input mechanism, such as a hardware keyboard, a trackball, or a five-way navigation pad. If your application requires a particular kind of input hardware, then you should declare it in your manifest with the <uses-configuration> element. However, it is rare that an application should require a certain input configuration.Device featuresThere are many hardware and software features that may or may not exist on a given Android-powered device, such as a camera, a light sensor, bluetooth, a certain version of OpenGL, or the fidelity of the touchscreen. You should never assume that a certain feature is available on all Android-powered devices (other than the availability of the standard Android library), so you should declare any features used by your application withthe <uses-feature> element.Platform VersionDifferent Android-powered devices often run different versions of the Android platform, such as Android 1.6 or Android 2.3. Each successive version often includes additional APIs not available in the previous version. In order to indicate which set of APIs are available, each platform version specifies an API Level (for example, Android 1.0 is API Level 1 and Android 2.3 is API Level 9). If you use any APIs that were added to the platform after version 1.0, you should declare the minimum API Level in which those APIs were introduced using the <uses-sdk> element.It's important that you declare all such requirements for your application, because, when you distribute your application on Google Play, the store uses these declarations to filter which applications are available on each device. As such, your application should be available only to devices that meet all your application requirements.For more information about how Google Play filters applications based on these (and other) requirements, see the Filters on Google Play document.Application ResourcesAn Android application is composed of more than just code—it requires resources that are separate from the source code, such as images, audio files, and anything relating to the visual presentation of the application. For example, you should define animations, menus, styles, colors, and the layout of activity user interfaces with XML files. Using application resources makes it easy to update various characteristics of your application without modifying code and—by providing sets of alternative resources—enables you to optimize your application for a variety of device configurations (such as different languages and screen sizes).For every resource that you include in your Android project, the SDK build tools define a unique integer ID, which you can use to reference the resource from your application code or from other resources defined in XML. For example, if your application c ontains an image file named logo.png (saved in the res/drawable/ directory), the SDK tools generate a resource IDnamed R.drawable.logo, which you can use to reference the image and insert it in your user interface.One of the most important aspects of providing resources separate from your source code is the ability for you to provide alternative resources for different device configurations. For example, by defining UI strings in XML, you can translate the strings into other languages and save those strings in separate files. Then, based on a language qualifier that you append to the resource directory's name (such as res/values-fr/ for French string values) and the user's language setting, the Android system applies the appropriate language strings to your UI.Android supports many different qualifiers for your alternative resources. The qualifier is a short string that you include in the name of your resource directories in order to define the device configuration for which those resources should be used. As another example, you should often create different layouts for your activities, depending on the device's screen orientation and size. For example, when the device screen is in portrait orientation (tall), you might want a layout with buttons to be vertical, but when the screen is in landscape orientation (wide), the buttons should be aligned horizontally. To change the layout depending on the orientation, you can define two different layouts and apply the appropriate qualifier to each layout's directory name. Then, the system automatically applies the appropriate layout depending on the current device orientation.For more about the different kinds of resources you can include in your application and how to create alternative resources for various device configurations, see theApplication Resources developer guide.安卓应用基础在Java编程语言编写的Android应用程序的Android的SDK工具编译代码以及与任何数据和到一个Android的包，一个归档文件档案资源的.apk后缀，所有的在一个单一的代码.apk文件被认为是一个应用程序，是Android的文件，供电设备来安装应用程序。
Android外文文献翻译11
Android Application Fundamentals nguage pil.th.code—alon.wit.an.dat.an.resourc.files—int.an Androi.package.a.archiv.an .apk suffix.Al.th.cod.i..single .apk.considere.t.b.on. applicatio.an.i.th..t.instal.th.application.Once installed on a device, each Android application lives in its own security sandbox:The Android operating system is a multi-user Linux system in which each application is a different user.e .I.(e.onl.b.th.syste.an.i.unknow.t.th.application). Th.syste.set.permission.fo.al.th.file.i.a.applicatio.s.tha.o e.I.assigne.t.tha.applicatio.ca.acces.them.Each process has its own virtual machine (VM), so an application's code runs in isolation from other applications.B.default.ever.applicatio.run.i.it.ow.Linu.process.Androi.st art.th.proces.whe.an.o.th.application'.component.nee.t.b.exe cuted.the.shut.dow.th.proces.whe.it'.n.longe.neede.o.whe.th. syste.mus.recove.memor.fo.othe.applications.I.thi.way.th.Androi.syste.implement.the principl.o.leas.pri vilege.Tha.is.eac.application.b.default.ha.acces.onl.t.th.co mponent.tha.i.require.t.d.it.wor.an.n.more.Thi.create..ver.s ecur.environmen.i.whic.a.applicatio.canno.acces.part.o.th.sy ste.fo.whic.i.i.no.give.permission.However, there are ways for an application to share data with other applications and for an application to access system services:It'.possibl.t.arrang.fo.tw.application.t.shar.th.sam.Lin e.ID.i.whic.cas.the.ar.abl.t.acces.eac.other'.files.T.co e.I.ca.als.ar rang.t.ru.i.th.sam.Linu.proces.an.shar.th.sam.V.(th.applicat ion.mus.als.b.signe.wit.th.sam.certificate).A.applicatio.ca.reques.permissio.t.acces.devic.dat.suc.a.th. user'.contacts.SM.messages.th.mountabl.storag.(S.card).camer a.Bluetooth.an.more.Al.applicatio.permission.mus.b.grante.b. e.a.instal.time.Tha.cover.th.basic.regardin.ho.a.Androi.applicatio.exist .withi.th.system.Th.res.o.thi.documen.introduce.yo.to:1.The core framework components that define your application.2.The manifest which you declare components and required device features for your application.3、Resource.tha.ar.separat.fro.th.applicatio.cod.an.allo.you.ap plicatio.t.gracefull.optimiz.it.behavio.fo..variet.o.devic.c onfigurations.Application Componentsponent.ar.th.essentia.buildin.block.o.a. ponen.i..differen.poin.throug.whic ponent.ar.actua.e e.an.som.depen.o.eac.other.bu.eac.on.exist .a.it.ow.entit.an.play..specifi.role—eac.on.i..uniqu.buildin.bloc.tha.help.defin.you.application' .overal.behavior.ponents.Eac.ty p.serve..distinc.purpos.an.ha..distinc.lifecycl.tha.define.h ponen.i.create.an.destroyed.Here are the four types of application components: ActivitiesAn activity e.interface. Fo.example.a.emai.applicatio.migh.hav.on.activit.tha.show..l pos.a.email.an.anothe.activit.fo.readin.emails.Althoug.th.activitie.wor.togethe.t.for e.experienc.i.th.emai.application.eac.on.i.indep enden.o.th.others.A.such..differen.applicatio.ca.star.an.on. o.thes.activitie.(i.th.emai.applicatio.allow.it).Fo.example. .camer.applicatio.ca.star.th.activit.i.th.emai.applicatio.th e.t.shar..picture.An activity is implemented as a subclass of Activity and you can learn more about it in the Activities developer guide. ServicesA service ponen.tha.run.i.th.backgroun.t.perfor. long-runnin.operation.o.t.perfor.wor.fo.remot.processes..ser e.interface.Fo.example..servic.migh.pla e.i.i..differen.application.o e.interactio ponent.suc.a.a.activity.ca.star.th .servic.an.le.i.ru.o.bin.t.i.i.orde.t.interac.wit.it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide. Content providersA conten.provider manage..share.se.o.applicatio.data.Y o.ca.stor.th.dat.i.th..a.SQLit.database.o.th.web.o.an.othe.p ersisten.storag.locatio.you.applicatio.ca.access.Throug.th.conten.provider.othe.application.ca.quer.o.eve.modif.th.dat.( i.th.conten.provide.allow.it).Fo.example.th.Androi.syste.pro er'rmation.A.such.an.applicatio.wit.th.prope.permission.ca.quer.par.o.t h.conten.provide.(suc.as ContactsContract.Data.t.rea.an.wri rmatio.abou..particula.person.efu.fo.readin.an.writin.dat.tha .i.privat.t.you.applicatio.an.no.shared.Fo.example.the Not. Pad e..conten.provide.t.sav.notes..conten.provide.i.implemente.a..subclas.of ContentProvider an.mus.implemen..standar.se.o.API.tha.enabl.othe.applicati rmation.se.the Conten.P roviders develope.guide.Broadcast receiversA broadcas.receiver ponen.tha.respond.t.system-w id.broadcas.announcements.Man.broadcast.originat.fro.th.syst em—fo.example..broadcas.announcin.tha.th.scree.ha.turne.off.th. batter.i.low.o..pictur.wa.captured.Application.ca.als.initia t.broadcasts—fo.example.t.le.othe.application.kno.tha.som.dat.ha.bee.down e.Althoug.broadcas .receiver.don'e.interface.the.may creat..statu.ba.notification e.whe..broadcas.even.occurs.Mor. commonly.though..broadcas.receive.i.jus.." ponent.an.i.intende.t.d..ver.minima.amoun.o.work.Fo.instance .i.migh.initiat..servic.t.perfor.som.wor.base.o.th.event. .broadcas.receive.i.implemente.a..subclas.of BroadcastRecei ver an.eac.broadcas.i.delivere.a.an Intent object.Fo.mor. information.se.th.BroadcastReceiver class..uniqu.aspec.o.th.Androi.syste.desig.i.tha.an.applicatio. ca.star.anothe.application’.component.Fo.example.i.yo.wan.t e.t.captur..phot.wit.th.devic.camera.there'.probabl.anot .it.instea. o.developin.a.activit.t.captur..phot.yourself.Yo.don'.nee.t. incorporat.o.eve.lin.t.th.cod.fro.th.camer.application.Inste ad.yo.ca.simpl.star.th.activit.i.th.camer.applicatio.tha.cap plete.th.phot.i.eve.returne.t.you.applica er.i.seem.a.i.th.camer.i.actuall..p ar.o.you.application.ponent.i.start.th.proces.fo.tha.ap plicatio.(i.it'.no.alread.running.an.instantiate.th.classe.n ponent.Fo.example.i.you.applicatio.start.th.ac tivit.i.th.camer.applicatio.tha.capture..photo.tha.activit.r un.i.th.proces.tha.belong.t.th.camer.application.no.i.you.application'.process.Therefore.unlik.application.o.mos.othe.sy stems.Androi.application.don'.hav..singl.entr.poin.(there'.n o main() function.fo.example).Becaus.th.syste.run.eac.applicatio.i..separat.proces.wit. tha.restric.acces.t.othe.applications.you.applicatio.canno.d ponen.fro.anothe.application.Th.Androi.sy ponen.i.anothe.application .yo.mus.delive..messag.t.th.syste.tha.specifie.your intent ponen.fo.you.Activating Componentsponen.types—activities.services.an.broadcas.receivers—ar.activate.b.a.asynchronou.messag.calle.an intent.Intent.b ponent.t.eac.othe.a.runtim.(yo.ca.thin.o.the ponents).whet ponen.belong.t.you.applicatio.o.another.An intent is created with an Intent object, which defines a message to activate either a specific component or a specific type of component—an intent can be either explicit or implicit, respectively.Fo.activitie.an.services.a.inten.define.th.actio.t.perfor .(fo.example.t."view.o."send.something.an.ma.specif.th.UR.o. th.dat.t.ac.o.(ponen.bein.starte.m igh.nee.t.know).Fo.example.a.inten.migh.conve..reques.fo.a.a ctivit.t.sho.a.imag.o.t.ope..we.page.I.som.cases.yo.ca.star.a.activit.t.receiv..result.i.whic.case.th.activit.als.return .th.resul.i.an Intent (fo.example.yo.ca.issu.a.inten.t.le. e.pic..persona.contac.an.hav.i.returne.t.you—th.retur.inten.include..UR.pointin.t.th.chose.contact).For broadcast receivers, the intent simply defines the announcement being broadcast (for example, a broadcast to indicate the device battery is low includes only a known action string that indicates "battery is low").ponen.type.conten.provider.i.no.activate.b. intents.Rather.i.i.activate.whe.targete.b..reques.fro.a Con tentResolver.Th.conten.resolve.handle.al.direc.transaction.w ponen.that'.performin.trans action.wit.th.provide.doesn'.nee.t.an.instea.call.method.o.t he ContentResolver ye.o.abstractio.bet rmatio.(f o.security).There are separate methods for activating each type of component:You can start an activity (or give it something new to do) by passingan Intent to startActivity()or startActivityForResult( )(when you want the activity to return a result).Yo.ca.star..servic.(o.giv.ne.instruction.t.a.ongoin.serv ice.b.passin.an Intent to startService().O.yo.ca.bin.t.th .servic.b.passin.an Intent tobindService().You can initiate a broadcast by passing an Intent to methods like sendBroadcast(), sendOrderedBroadcast(),or sendStickyBroadcast().You can perform a query to a content provider bycalling query()on a ContentResolver.in.intents.se.the Intent.an.Inten .Filters ponent.i.als.provide.i.th.followin.documents: Activities, Services, BroadcastReceiver and Conten.Providers.Declaring components<?xm.version="1.0.encoding="utf-8"?><manifes....>..<applicatio.android:icon="@drawable/app_icon.png....> ....<activit.android:name="com.example.project.ExampleActivi ty".........android:label="@string/example_label....>....</activity>.........</application></manifest>In the <application>element, theandroid:icon attribute points to resources for an icon that identifies the application.In the <activity>element, the android:name at tribute specifies the fu lly qualified class name of theActivity subclass and the android:label attributes specifies a string to use as the user-visible label for the activity.You must declare all application components this way:1.<activity> elements for activities2.<service> elements for services3.<receiver> elements for broadcast receivers4.<provider> elements for content providersActivities.services.an.conten.provider.tha.yo.includ.i.yo u.sourc.bu.d.no.declar.i.th.manifes.ar.no.visibl.t.th.syste. and.consequently.ca.neve.run.However.broadcas.receiver.ca.b. eithe.declare.i.th.manifes.o.create.dynamicall.i.cod.(as Br oadcastReceiver objects.an.registere.wit.th.syste.b.callingregisterReceiver().Declaring component capabilitiesA.discusse.above.in .an In tent t.star.activities.services.an.broadcas.receivers.Yo.ca ponen.(ponen.c .i.th.intent.However.th.rea.powe.o.intent.lie.i.th.c oncep.o.inten.actions.Wit.inten.actions.yo.simpl.describ.th. typ.o.actio.yo.wan.t.perfor.(an.optionally.th.dat.upo.whic.y ou’ponen .o.th.devic.tha.ca.perfor.th.actio.an.star.it.I.ther.ar.mult ponent.tha.ca.perfor.th.actio.describe.b.th.intent.th e.The way the system identifies the components that can respond to an intent is by comparing the intent received to the intent filters provided in the manifest other applications on the device.ponen.i.you.application'.manifest.yo.ca .optionall.includ.inten.filter.tha.declar.th.capabilitie.o.t ponen.s.i.ca.respon.t.intent.fro.othe.applications.Yo.c ponen.b.addin.an <intent-f ilter> ponent'.declaratio.element.posin..n e.emai.migh.declar.a.inten.filte.i.it.manifes.entr.t.respon. t."send.intent.(i.orde.t.sen.email).A.activit.i.you.applicat io.ca.the.creat.a.inten.wit.th.“send.actio.(ACTION_SEND).whic.th.syste.matche.t.th.emai.ap plication’.“unche.i.whe.yo.invok.th.inten.with star tActivity().For more about creating intent filters, see the Intents and Intent Filters document.Declaring application requirementsTher.ar..variet.o.device.powere.b.Androi.an.no.al.o.the.p rovid.th.sam.feature.an.capabilities.I.orde.t.preven.you.app c.feature.neede.b.y ou.application.it'.importan.tha.yo.clearl.defin..pr.th.type. o.device.you.applicatio.support.b.declarin.devic.an.softwar. requirement.i.you.manifes.file.Mos.o.thes.declaration.ar.informationa.onl.an.th.syste.doe.no.rea.them.bu.externa.service er. whe.the.searc.fo.application.fro.thei.device.e.API.int roduce.i.Androi.2..(AP.Level 7).yo.shoul.declar.thes.a.requ irement.i.you.manifes.file.Tha.way.device.tha.do not hav.. camer.an.hav.a.Androi.version lower tha.2..canno.instal.yo u.applicatio.fro.Googl.Play.e.th.camera .bu.doe.not require it.I.tha.case.you.applicatio.mus.perfo r..chec.a.runtim.t.determin.i.th.devic.ha..camer.an.disabl.a .th.camer.i.on.i.no.available.Here are some of the important device characteristics that you should consider as you design and develop your application: Screen size and densityI.orde.t.categoriz.device.b.thei.scree.type.Androi.defin e.tw.characteristic.fo.eac.device.scree.siz.(th.physica.dime 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Leve..an.Androi.2..i.AP.Leve.9).an.API.tha.wer.adde. t.th.platfor.afte.versio.1.0.yo.shoul.declar.th.minimu.AP.Le in.the <uses-sdk> eleme nt.It'.importan.tha.yo.declar.al.suc.requirement.fo.you.appl ication.because.whe.yo.distribut.you.applicatio.o.Googl.Play e.thes.declaration.t.filte.whic.application.ar.av ailabl.o.eac.device.A.such.you.applicatio.shoul.b.availabl.o nl.t.device.tha.mee.al.you.applicatio.requirements.For more information about how Google Play filters applications based on these (and other) requirements, see the Filters on Google Play document.Application Resourcespose.o.mor.tha.jus.code—i.require.resource.tha.ar.separat.fro.th.sourc.code.suc.a.im ages.audi.files.an.anythin.relatin.t.th.visua.presentatio.o. th.application.Fo.example.yo.shoul.defin.animations.menus.st e.interface.wit.XM.files .Usin.applicatio.resource.make.i.eas.t.updat.variou.characte ristic.o.you.applicatio.withou.modifyin.cod.and—b.providin.set.o.alternativ.resources—enable.yo.t.optimiz.you.applicatio.fo..variet.o.devic.config uration.(nguage.an.scree.sizes).Fo.ever.resourc.tha.yo.includ.i.you.Androi.project.th.SD. .t.referenc.th .resourc.fro.you.applicatio.cod.o.fro.othe.resource.define.i .XML.Fo.example.i.you.applicatio.contain.a.imag. logo.png (save.i.the res/drawable/ directory).th.SD.tool.generat..r d .t.referenc.th. e.interface.On.o.th.mos.importan.aspect.o.providin.resource.separat.f ro.you.sourc.cod.i.th.abilit.fo.yo.t.provid.alternativ.resou rce.fo.differen.devic.configurations.Fo.example.b.definin.U. nguage.an.snguag.qualifie .tha.yo.appen.t.th.resourc.directory'.nam.(suc.as res/value s-fr/ er'.languag.setting.th. nguag.string.t.you.UI.Androi.support.man.different qualifiers fo.you.alternat iv.resources.Th.qualifie.i..shor.strin.tha.yo.includ.i.th.na m.o.you.resourc.directorie.i.orde.t.defin.th.devic.configura ed.A.anothe.example.yo.s yout.fo.you.activities.dependin.o .th.device'.scree.orientatio.an.size.Fo.example.whe.th.devic .scree.i.i.portrai.orientatio.(tall)you.wit. ndscap.orientatio. (wide)yo yout.a yout'.Th you.dependin .o.th.curren.devic.orientation.For more about the different kinds of resources you can include in your application and how to create alternative resources for various device configurations, see theApplication Resources developer guide.安卓应用基础在Java编程语言编写的Android应用程序的Android的SDK工具编译代码以及及任何数据和到一个Android的包, 一个归档文件档案资源的.apk后缀, 所有的在一个单一的代码.apk文件被认为是一个应用程序, 是Android的文件, 供电设备来安装应用程序。
外文翻译---安卓系统的基本描述
附录二外文文献（原文）The basic of description of android system The mainstream of the next generation of open operating systems will not be on the desktop, but will appear in the phone that we carry every day. Open environment will lead these new applications may be integrated into these online services that already exist, of course, as with growing data services on mobile phones support the security flaws on the phone is also becoming increasingly clear. The nature of the next-generation operating system, whether to provide a complete integrated security platform.By the Open Mobile Alliance (open Handset Alliance led by Google) developed the android system is a widely optimistic about an open source phone system, the system provides a basic operating system, a middle ware application layer, a java development tools and a system Application collector (collection of system applications). The android the SDK since 2007 on the release of the first android phone in October 2008 before the birth. Google opened since then on his own time, Taiwan's HTC, the manufacturer of the T-Mobile G1 estimate G1 shipments have more than one million at the end of 2008. According to industry insiders expect the G1 mobile phone sales in 2009 continue. Many other mobile phone suppliers in the near future plans to support this system.Around an android and a huge developer community has been established, while a lot of new products and applications on the android. Android's main selling point is that it enables developers to seamlessly expand online services to mobile phones. This is the most obvious example is Google's tightly integrated with Gmail, Calendar and Contacts Web applications through the system. Users only need to provide an android user name and password, the phone automatically sync with Google services. The other vendors are quickly adapt their existing instant messaging, social networking and gaming services. Android and many companies find new ways to integrate their existing business to the android.Traditional desktop and server operating system has been working for the integration of security features. These individuals and business applications on a single platform is very good, however a business phone platform like android is not very useful. It gives the hope of many researchers. Android is not parked in the body for other platform application support: the implementation of the application depends on a top-level JA V A middle ware, the middle ware running on the embedded Linux kernel. Therefore, developers should deploy their applications to the Android mustuse a custom user interface environment.In addition, the android system applications limit the application to call each other API collaboration, and the other to authenticate the user application. Although these applications have certain safety features, some of our experienced developers to create Android applications who revealed that the design of security applications is not always straight forward. Android uses a simple permission label distribution mode to restrict access to resources, but the reasons for the necessity and convenience of other applications, the designers have increased the confusion on this system. This paper attempts to explain the complexity of the Android security, and pay attention to some of the possible development defects and application security. We try to draw some lessons learned, and hope that the safety of the future.Android application framework for developers is a mandatory framework. It does not have a main () function function or a single entry point for the implementation of the contrary, the developer must in the design of application components. We developed applications to help the API of the android sdkThe Android system defines four kinds of component type.Activity component that defines the application user interface. Usually, the application developer defines each activity screen. Activity can start, it may pass and return values. Can be handled at a time only a keyboard system Activity, all other Activity will be suspended at this time.Service components perform background processing. The need for some operations when an activity, after the disappearance of the user interface (such as downloading a file or playing music), it usually take such action specially designed services. Developers can also use a special daemon at system startup, the service is usually defined a remote procedure call (RPC), and other system components can be used to send the interface command and retrieve data, as well as to register a callback function.ContentProvider component storage and share data with relational database interfaces. Each Content supplier has an associated "rights" to describe its contents contains. Other components when used as a handle to execute SQL queries (eg SELECT, INSERT, or DELETE content. Content suppliers are typically stored the values on the database records, data retrieval is a special case, the file is also shared by the content provider interface.The components of the broadcast receiver as to send a message from the mailbox to the application. Typically, the broadcast message, the application code implicit destination. Therefore, the radio receiver subscribe to these destinations receive messages sent to it. The application code can also be solved explicitly broadcast receivers, including the name space allocation.The main mechanism of the interaction of the components of the Component Interaction, is an intent, which is a simple message object, which contains a destination address and data components. The Android API defines his approach into intent, and use that information to initiate an activity such as start an activity (startActivity (An intent)) start services (the startService (An intent)) and radio (sendBroadcast (An intent)). Android framework to inform the calls to these methods began to perform in the target application code. This process, the internal components of communication is called an action. Simply put, the Intent object defined in the "Intent to implement the" action ". One of the most powerful features of the Android is allowed a variety of intent addressing mechanism. The developer can solve the space of a target component using its applications, they can also specify an implicit name. In the latter case, the system determines the best components of an action by considering the installed applications and user choice.Implicit name is called the action string because of his special type of the requested action. Such as a view action string, in an intent data field points to an image file, the system will directly referring to the preferred image viewer.Developers can also use the action string a large number of radio to send and receive. Receiver at the receiving end, the developers use an intent filter to customize the special action string. Android Department, including the additional goal of the resolution rules, but an optional string type of data manipulation is the most common.Android applications are written in the Java programming language.The compiled Java code —along with any data and resource files required by the application —is bundled by the apt tool into an Android package,an archive file marked by an .apk suffix.This file is the vehicle for distributing the application and installing it on mobile devices;it's the file users download to their devices.All the code in a single.apk file is considered to be one application.In many ways,each Android application lives in its own world:（1）By default,every application runs in its own Linux process.Android starts the process when any of the application's code needs to be executed,and shuts down the process when it's no longer needed and system resources are required by otherapplications.（2）Each process has its own virtual machine(VM),so application code runs in isolation from the code of all other applications.（3）By default,each application is assigned a unique Linux user ID.Permissions are set so that the application's files are visible only to that user and only to the application itself —altough there are ways to export them to other applications as well.It's possible to arrange for two applications to share the same user ID,in while case they will be able to see each other's files.To conserve system resources,applications with the same ID can also arrange to run in the same Linux process,sharing the same VM.Application ComponentsA central feature of Android is that one application can make use of elements of other application (provided those application permit it).For example,if your application needs to display a scrolling list of images and another application has developed a suitable scroller and made it available to others,you can call upon that scroller to do the work,rather than develop your own.Your application doesn't incorporate the code of the other application or link to it.Rather,it simply starts up that piece of the other application when the need arises.For this to work,the system must be able to start an application process when any part of it is needed,and instantiate the Java objects for that part.Therefore,unlike applications on most other systems,Android applications don't have a single entry point for everything in the application(no main()function,for example).Rather,they have essential components that the system can instantiate and run as needed.There are four types of components:ActivitiesAn activity presents a visual user interface for one focused endeavor the user can undertake.For example,an activity might present a list of menu items users can choose from or it might display photographs along with their captions.A text messaging application might have one activity that shows a list of contacts to send messages to,a second activity to write the message to the chosen contact,and other activities to review old messages or change or change settings.Tough they work together to form a cohesive user interface,each activity is independent of the others.Each one is implemented as a subclass of the Activity base class.An application might consist of just one activity or,like the text messaging application just mentioned,it may contain several.What the activities are,and how many there are depends,of course,on the application and its design.Typically,one of the activities is marked as the first one that should be presented to the user when the application is launched.Moving from one activity to another is accomplished by having the current activity start the next one.Each activity is given a default window to draw in.Typically,the window fills the screen,but it might be smaller than the screen and float on top of other windows.An activity can also make use of additional windows —for example,a pop-up dialog that calls for a user response in the midst of the activity,or a window that presents users with vital information when they select a particular item on-screen.The visual content of the window is provided by a hierarchy of views —objects derived from the base View class.Each view controls a particular rectangular space within the window.Parent views contain and organize the layout of their children.Leaf views(those at the bottom of the hierarchy)draw in the rectangles they control and respond to user actions directed at that space.Thus,views are where the activity's interaction with the user takes place.For example,a view might display a small image and initiate an action when the user taps that image.Android has a number of ready-made views that you can use —including buttons,text fields,scroll bars,menu items,check boxes,and more.A view hierarchy is placed within an activity's window by the Activity.setContentView()method.The content view is the View object at the root of the hierarchy.(See the separate User Interface document for more information on views and the hierarchy.)ServicesA service doesn't have a visual user interface,but rather runs in the background for an indefinite period of time.For example,a service might play background music as the user attends to other matters,or it might fetch data over the network or calculate something and provide the result to activities that need it.Each service extends the Service base class.A prime example is a media player songs from a play list.The player application would probably have one or more activities that allow the user to choose songs and start playing them.However,the music playback itself would bot be handled by an activity because users will expect the music to keep the music going,the media player activity could start a service to run in the background.The system would then keep themusic playback service running even after the activity that started it leaves the screen.It's possible to connect to (bind to)an ongoing service(and start the service if it's not already running).While connected,you can communicate with the service through an interface that the service exposes.For the music service,this interface might allow users to pause,rewind,stop,and restart the playback.Like activities and the other components,services run in the main thread of the application process.So that they won't block other components or the user interface,they often spawn another thread for time-consuming tasks(like music playback).See Processes and Thread,later.Broadcast receiversA broadcast receiver is a component that does nothing but receive and react to broadcast announcements.Many broadcasts originate in system code —for example,announcements that the timezone has changed,that the battery is low,that a picture has been taken,or that the user changed a language preference.Applications can also initiate broadcasts —for example,to let other applications know that some data has been downloaded to the device and is available for them to use.An application can have any number of broadcast receivers to respond to respond to respond to any announcements it considers important.All receivers extend the BroadcastReceiver base class.Broadcast receivers do not display a user interface.However,they may start an activity in response to the information they receive,or they may use the NotificationManager to alert the user.Notifications can get the user's attention in various ways —flashing the backlight,vibrating the device,playing a sound,and so on,They typically place a persistent icon in the status bar,which users can open to get the message.Content providersA content provider makes a specific set of the application's data available to other applications.The data can be stored in the file system,in an SQLite database,or in any other manner that makes sense.The content provider extends the ContentProvider base class to implement a standard set of methods that enable other applications to retrieve and store data of the type it controls.However,applications do not call these methods directly.Rather they use a ContentResolver object and call its methods instead.A ContentResolver can talk to any content provider;it cooperates with the provider to manage any interprocess communication that's involved.See the separate Content Providers document for more information on using content providers.Whenever there's a request that should be handled by a particular component,Android makes sure that the application process of the component is running,starting it if necessary,and that an appropriate instance of the component is available,creating the instance if necessary.Activating components:intentsContent providers are activated when they're targeted by a request from a ContentResolver.The other three components —activities,services,and broadcast receivers —are activated by asynchronous messages called intents.An intent is an Intent object that holds the content of the message.For activities and services,it names the action being requested and specifies the URI of the data to act on,among other things.For example,it might convey a request for an activity to present an image t the user or let the user edit some text.For broadcast receivers,the Intent object names the action being announced.For example,it might announce to interested parties that the camera button has been pressed.There are separate methods for activating each type of component:1.An activity is launched(or given something new to do)by passing an Intent object to Context.startActivity() or Activity.startActivityForResult().The responding activity can look at the initial intent that caused it to be launched by calling its getIntent() method.Android calls the activity's onNewIntent()method to pass it any subsequent intents.One activity often starts the next one.If it expects a result back from the activity it's starting,it calls startActivityForResult() instead of startActivity().For example,if it starts an activity that lets the user pick a photo,it might expect to be returned the chosen photo.The result is returned in an Intent object that's passed to the calling activity's onActivityResult() method.2.A service is started(or new instructions are given to an ongoing service)by passing an Intent object to Context.startService().Android calls the service's onStart() method and passes it the Intent object.Similarly,an intent can be passed to Context.bindService() to establish an ongoing connection between the calling component and a target service.The service receives the Intent object in an onBind() call.(If the service is not already running,bindService() can optionally start it.)For example,an activity might establish a connection with the music playback service mentioned earlier so that it can provide the user with the means(a user interface)for controlling the playback.The activity would call bindService() to set up thatconnection,and then call methods defined by the service to affect the playback.A later section,Remote procedure calls,has more details about binding to a service.3.An application can initiate a broadcast by passing an Intent object to methods like Context.sendStickyBroadcast() in any of their variations.Android delivers the intent to all interested broadcast receivers by calling their onReceive() methods.For more on intent messages,see the separate article,Intents and Intent Filters.Shutting down componentsA content provider is active only while it's responding to a request from a ContentResolver.And a broadcast receiver is active only while it's responding to a broadcast message.So there's no need to explicitly shut down these components.Activities,on the other hand,provide the user interface.They're in a long-running conversation with the user and may remain active,even when idle,as long time.So Android has methods to shut down activities and services in an orderly way:1.An activity can be shut down by calling its finish() method.Onte activity can shut down another activity (one it started with startActivityForResult())by calling finishActivity().2.A service can be stopped by calling its stopSelf() method,or by calling Context.stopService().Components might also be shut down by the system when they are no longer being used or when Android must reclaim memory for more active components.A later section,Component Lifecycles,discusses this possibility and its ramifications in more detail.The manifest fileBefore Android can start an application component,it must learn that the component exists.Therefore,applications declare their components in a manifest file that's bundled into the Android package,the .apk file that also holds the application's code,files, and resources.The manifest is a structured XML file and is always named AndroidManifest.xml for all applications.It does a number of things in addition to declaring the application's components,such as naming any libraries the application needs to be linked against(besides the default Android library)and identifying any permissions the application expects to be granted.But the principal task of the manifest is to inform Android about the application's components.For example,an activity might be declared as follows:The name attribute of the <activity>element names the Activity subclass that implements the activity.The icon and label attributes point to resource files containing an icon and label that can be displayed to users to resource files containing an icon and label that can be displayed to users to represent the activity.The other components are declared in a similar way —<service>elements for services,<receiver>elements for broadcast receivers,and<provider>elements for content providers.Activities,services,and content providers that are not declared in the manifest are not visible to the system and are consequently never run.However,broadcast receivers can either be declared in the manifest,or they can be created dynamically i code (as BroadcastReceiver objects)and registered with the system by calling Context.registerReceiber().For more on how to structure a manifest file for your application,see The Android Manifest.xml File.Intent filtersAn Intent object can explicitly name a target component.If it does,Android finds that component(based on the declarations in the manifest file)and activates it.But if a target is not explicitly named,Android must locate the best component to respond to the intent.It does s by comparing the Intent object to the intent filters of potential targets.A component's intent filters inform Android of the kinds of intents the component is able to handle.Like other essential information about the component,they're declared in the manifest.Here's an extension of the previous example that adds two intent filters to the activity:The first filter in the example —the combination of the action "android.intent.action.MAIN"and the category "UNCHER"—is a common one.It marks the activity as one that should be represented in the application launcher,the screen listing applications users can launch on the device.In other words,the activity is the entry point for the application,the initial one users would see when they choose the application in the launcher.The component can have any number of intent filters,each one declaring a different set of capabilities.If it doesn't have any filters,it can be activated only by intents that explicitly name the component as the target.For a broadcast receiver that's created and registered in code,the intent filter is instantiated directly as an IntentFilter object.All other filters are set up in the manifest.For more on intent filters,see a separate document, Intents and Intent Filters.附录三外文文献（译文）安卓系统的基本描述下一代开放操作系统的主流将不会在桌面上，但是将会出现在我们每天携带的手机上。
安卓单词(国外英文资料)
安卓单词(国外英文资料)在当今数字化的时代，安卓操作系统已经成为全球范围内使用最广泛的移动操作系统之一。
安卓不仅为用户提供了丰富的应用和功能，还推动了移动技术的创新和发展。
然而，对于许多人来说，安卓系统中的许多专业术语和概念可能显得有些陌生和难以理解。
为了帮助用户更好地了解安卓系统，本文将介绍一些与安卓相关的常用单词和术语，并提供相关的英文资料，以便读者能够更深入地了解安卓系统的各个方面。
1. Android：安卓操作系统的名称，源自于英文单词“android”，意为“”。
2. APK：安卓应用程序的安装包文件格式，全称为“Android Package”。
3. Dalvik：安卓系统中的一个虚拟机，用于运行安卓应用程序。
4. ROM：安卓系统的固件版本，全称为“ReadOnly Memory”。
5. Root：对安卓系统进行解锁，以获得更高的权限和更广泛的控制。
6. SDK：安卓软件开发工具包，全称为“Software Development Kit”。
7. UI：用户界面，全称为“User Interface”。
8. UX：用户体验，全称为“User Experience”。
9. Widget：安卓系统中的一个小工具，可以显示在主屏幕上，提供快捷的操作和显示信息。
10. Fragment：安卓系统中的一个组件，用于实现用户界面的模块化。
1. Android Developers：安卓开发者官方网站，提供了丰富的文档、教程和资源，适合开发者学习安卓编程。
2. XDA Developers：一个安卓社区，提供了大量的安卓相关资讯、教程和讨论，适合对安卓系统感兴趣的用户。
3. Android Central：一个专注于安卓系统的新闻网站，提供了最新的安卓资讯、评测和教程。
4. Stack Overflow：一个编程问答社区，提供了大量的安卓编程问题解答，适合开发者解决安卓编程中的问题。
5. Reddit：一个社交新闻网站，有一个专门的安卓子版块，提供了大量的安卓相关讨论和分享。
安卓系统权限中英文对照
安卓系统权限中英文对照网上搜集的安卓系统软件的权限中英文对照程序执行需要读取到安全敏感项必需在androidmanifest.xml中声明相关权限请求, 完整列表如下:android.permission.ACCESS_CHECKIN_PROPERTIES允许读写访问”properties”表在checkin数据库中，改值可以修改上传( Allows read/write access to the “properties” table in the checkin database, to change value s that get uploaded) android.permission.ACCESS_COARSE_LOCA TION允许一个程序访问CellID或WiFi热点来获取粗略的位置(Allows an application to access coarse (e.g., Cell-ID, WiFi) location) copyright dedecmsandroid.permission.ACCESS_FINE_LOCA TION允许一个程序访问精良位置(如GPS) (Allows an application to access fine (e.g., GPS) location) android.permission.ACCESS_LOCA TION_EXTRA_COMMANDS 允许应用程序访问额外的位置提供命令(Allows an application to access extra location provider commands)android.permission.ACCESS_MOCK_LOCA TION允许程序创建模拟位置提供用于测试(Allows an application to create mock location providers for testing)android.permission.ACCESS_NETWORK_STA TE允许程序访问有关GSM网络信息(Allows applications to access information about networks) android.permission.ACCESS_SURFACE_FLINGER允许程序使用SurfaceFlinger底层特性(Allows an application to use SurfaceFlinger’s low level features)android.permission.ACCESS_WIFI_STA TE允许程序访问Wi-Fi网络状态信息(Allows applications to accessinformation about Wi-Fi networks)android.permission.ADD_SYSTEM_SERVICE允许程序发布系统级服务(Allows an application to publish system-level services).android.permission.BA TTERY_STA TS允许程序更新手机电池统计信息(Allows an application to update the collected battery statistics) android.permission.BLUETOOTH允许程序连接到已配对的蓝牙设备(Allows applications to connect to paired bluetooth devices) android.permission.BLUETOOTH_ADMIN允许程序发现和配对蓝牙设备(Allows applications to discover and pair bluetooth devices) android.permission.BRICK 请求能够禁用设备(非常危险)(Required to be able to disable the device (very *erous!).) android.permission.BROADCAST_PACKAGE_REMOVED 允许程序广播一个提示消息在一个应用程序包已经移除后(Allows an application to broadcast a notification that an application package has been removed)android.permission.BROADCAST_STICKY允许一个程序广播常用intents(Allows an application to broadcast sticky intents) /doc/926213707.html,android.permission.CALL_PHONE允许一个程序初始化一个电话拨号不需通过拨号用户界面需要用户确认(Allows an application to initiate a phone call without going through the Dialer user interface for the user to confirm the call being placed.)android.permission.CALL_PRIVILEGED允许一个程序拨打任何号码，包含紧急号码无需通过拨号用户界面需要用户确认(Allows an application to call any phone number, including emergency numbers, without going through the Dialer user interface for the user to confirm the call being placed) android.permission.CAMERA请求访问使用照相设备(Required to be able to access the camera device. )android.permission.CHANGE_COMPONENT_ENABLED_STA TE允许一个程序是否改变一个组件或其他的启用或禁用(Allows an application to change whether an application component (other than its own) is enabled or not. )android.permission.CHANGE_CONFIGURA TION允许一个程序修改当前设置，如本地化(Allows an application to modify the current configuration, such as locale. )android.permission.CHANGE_NETWORK_STA TE允许程序改变网络连接状态(Allows applications to change network connectivity state) android.permission.CHANGE_WIFI_STA TE允许程序改变Wi-Fi连接状态(Allows applications to change Wi-Fi connectivity state) android.permission.CLEAR_APP_CACHE 允许一个程序清楚缓存从所有安装的程序在设备中(Allows an application to clear the caches of all installed applications on the device. )android.permission.CLEAR_APP_USER_DA TA允许一个程序清除用户设置(Allows an application to clear user data)android.permission.CONTROL_LOCA TION_UPDA TES允许启用禁止位置更新提示从无线模块(Allows enabling/disabling location update notifications from the radio. ) copyright dedecmsandroid.permission.DELETE_CACHE_FILES允许程序删除缓存文件(Allows an application to delete cache files)android.permission.DELETE_PACKAGES允许一个程序删除包(Allows an application to delete packages) android.permission.DEVICE_POWER允许访问底层电源管理(Allows low-level access to power management)android.permission.DIAGNOSTIC允许程序RW诊断资源(Allows applications to RW to diagnostic resources. )android.permission.DISABLE_KEYGUARD允许程序禁用键盘锁(Allows applications to disable the keyguard ) /doc/926213707.html, android.permission.DUMP允许程序返回状态抓取信息从系统服务(Allows an application to retrieve state dump information from system services.) android.permission.EXPAND_STA TUS_BAR允许一个程序扩展收缩在状态栏,android开发网提示应该是一个类似windows mobile中的托盘程序(Allows an application to expand or collapse the status bar. )android.permission.FACTORY_TEST作为一个工厂测试程序，运行在root用户(Run as a manufacturer test application, running as the root user. ) android.permission.FLASHLIGHT访问闪光灯,android开发网提示htc Dream不包含闪光灯(Allows access to the flashlight ) android.permission.FORCE_BACK 允许程序强行一个后退操作是否在顶层activities(Allows an application to force a BACK operation on whatever is the top activity. )android.permission.FOTA_UPDA TE暂时不了解这是做什么使用的，android开发网分析可能是一个预留权限.android.permission.GET_ACCOUNTS访问一个帐户列表在Accounts Service中(Allows access to the list of accounts in the Accounts Service)android.permission.GET_PACKAGE_SIZE允许一个程序获取任何package占用空间容量(Allows an application to find out the space used by any package. ) android.permission.GET_TASKS允许一个程序获取信息有关当前或最近运行的任务，一个缩略的任务状态，是否活动等等(Allows an application to get information about the currently or recently running tasks: a thumbnail representation of the tasks, what activities are running in it, etc.) android.permission.HARDWARE_TEST允许访问硬件(Allows access to hardware peripherals. )android.permission.INJECT_EVENTS允许一个程序截获用户事件如按键、触摸、轨迹球等等到一个时间流，android 开发网提醒算是hook技术吧(Allows an application to inject user events (keys, touch, trackball) into the event stream and deliver them to ANY window.)android.permission.INSTALL_PACKAGES允许一个程序安装packages(Allows an application to install packages. )android.permission.INTERNAL_SYSTEM_WINDOW允许打开窗口使用系统用户界面(Allows an application to open windows that are for use by parts of the system user interface. ) android.permission.INTERNET允许程序打开网络套接字(Allows applications to open network sockets)android.permission.MANAGE_APP_TOKENS允许程序管理(创建、催后、z- order默认向z轴推移)程序引用在窗口管理器中(Allows an application to manage (create, destroy, Z-order) application tokens in the window manager. ) android.permission.MASTER_CLEAR目前还没有明确的解释，android开发网分析可能是清除一切数据，类似硬格机android.permission.MODIFY_AUDIO_SETTINGS允许程序修改全局音频设置(Allows an application to modify global audio settings)android.permission.MODIFY_PHONE_STA TE允许修改话机状态，如电源，人机接口等(Allows modification of the telephony state – power on, mmi, etc. )android.permission.MOUNT_UNMOUNT_FILESYSTEMS允许挂载和反挂载文件系统可移动存储(Allows mounting and unmounting file systems for removable storage. )android.permission.PERSISTENT_ACTIVITY允许一个程序设置他的activities显示(Allow an application to make its activities persistent. )android.permission.PROCESS_OUTGOING_CALLS允许程序监视、修改有关播出电话(Allows an application to monitor, modify, or abort outgoing calls) 内容来自dedecms android.permission.READ_CALENDAR允许程序读取用户日历数据(Allows an application to read the user’s calendar data.)android.permission.READ_CONTACTS允许程序读取用户联系人数据(Allows an application to read the user’s contacts data.)android.permission.READ_FRAME_BUFFER允许程序屏幕波或和更多常规的访问帧缓冲数据(Allows an application to take screen shots and more generally get accessto the frame buffer data)android.permission.READ_INPUT_STA TE允许程序返回当前按键状态(Allows an application to retrieve the current state of keys and switches. )android.permission.READ_LOGS允许程序读取底层系统日志文件(Allows an application to read the low-level system log files. ) android.permission.READ_OWNER_DA TA允许程序读取所有者数据(Allows an application to read the owner’s data) /doc/926213707.html, android.permission.READ_SMS允许程序读取短信息(Allows an application to read SMS messages.)android.permission.READ_SYNC_SETTINGS允许程序读取同步设置(Allows applications to read the sync settings)android.permission.READ_SYNC_STA TS允许程序读取同步状态(Allows applications to read the sync stats)android.permission.REBOOT请求能够重新启动设备(Required to be able to reboot the device. )android.permission.RECEIVE_BOOT_COMPLETED允许一个程序接收到ACTION_BOOT_COMPLETED广播在系统完成启动(Allows an application to receive the ACTION_BOOT_COMPLETED that is broadcast after the system finishes booting. )android.permission.RECEIVE_MMS允许一个程序监控将收到MMS彩信,记录或处理(Allows an application to monitor incoming MMS messages, to record orperform processing on them. )android.permission.RECEIVE_SMS允许程序监控一个将收到短信息，记录或处理(Allows an application to monitor incoming SMS messages, to record or perform processing on them.)android.permission.RECEIVE_WAP_PUSH允许程序监控将收到W AP PUSH信息(Allows an application to monitor incoming WAP push messages. )android.permission.RECORD_AUDIO允许程序录制音频(Allows an application to record audio)android.permission.REORDER_TASKS允许程序改变Z轴排列任务(Allows an application to change the Z-order of tasks)android.permission.RESTART_PACKAGES允许程序重新启动其他程序(Allows an application to restart other applications)android.permission.SEND_SMS允许程序发送SMS短信(Allows an application to send SMS messages)android.permission.SET_ACTIVITY_WA TCHER允许程序监控或控制activities已经启动全局系统中Allows an application to watch and control how activities are started globally in the system. 内容来自dedecmsandroid.permission.SET_ALWAYS_FINISH允许程序控制是否活动间接完成在处于后台时Allows an application to control whether activities are immediately finished when put in the background.android.permission.SET_ANIMA TION_SCALE修改全局信息比例(Modify the global animation scaling factor.) android.permission.SET_DEBUG_APP配置一个程序用于调试(Configure an application for debugging.)android.permission.SET_ORIENTA TION允许底层访问设置屏幕方向和实际旋转(Allows low-level access to setting the orientation (actually rotation) of the screen.) android.permission.SET_PREFERRED_APPLICA TIONS允许一个程序修改列表参数PackageManager.addPackageT oPreferred() 和PackageManager.removePackageFromPreferred()方法(Allows an application to modify the list of preferred applications with the PackageManager.addPackageT oPreferred() and PackageManager.removePackageFromPreferred() methods.) android.permission.SET_PROCESS_FOREGROUND允许程序当前运行程序强行到前台(Allows an application to force any currently running process to be in the foreground.) android.permission.SET_PROCESS_LIMIT允许设置最大的运行进程数量(Allows an application to set the maximum number of (not needed) application processes that can be running. ) copyright dedecmsandroid.permission.SET_TIME_ZONE允许程序设置时间区域(Allows applications to set the system time zone)android.permission.SET_WALLPAPER允许程序设置壁纸(Allows applications to set the wallpaper ) android.permission.SET_WALLPAPER_HINTS允许程序设置壁纸hits(Allows applications to set the wallpaper hints)android.permission.SIGNAL_PERSISTENT_PROCESSES允许程序请求发送信号到所有显示的进程中(Allow an application to request that a signal be sent to all persistentprocesses)android.permission.STA TUS_BAR允许程序打开、关闭或禁用状态栏及图标Allows an application to open, close, or disable the status bar and its icons.android.permission.SUBSCRIBED_FEEDS_READ允许一个程序访问订阅RSS Feed内容提供(Allows an application to allow access the subscribed feeds ContentProvider. )android.permission.SUBSCRIBED_FEEDS_WRITE系统暂时保留改设置,android开发网认为未来版本会加入该功能。
八大英文文献翻译神器
你值得拥有的八大英文文献翻译神器不管是做科研还是写SCI论文，开始都需要阅读大量的文献，做课题至少查阅600篇，粗看300篇，细看100篇，研读50篇，在看到一叠叠论文后，由于语言问题，往往会觉得无从下手，下面分享几款常用的文献翻译神器。
1、谷歌浏览器翻译优点：页面简洁，使用方便，随开随用，多种语言随时切换，只要有网就能翻译。
缺点：功能比较单一，排版比较乱，界面不是很美观。
2、SCI Translate9.0目前有9.0普通版以及VIP版，VIP版内置Google 人工智能云翻译引擎，翻译精准度很强；没有广告。
3、LinggleLinggle是一个可用来进行英语语法、句子写作的工具，可为学习者提供更准确的英文写作建议。
4、NetSpeakNetSpeak是一个提供免费线上单词、词组、语句翻译的工具，其特点是可以在线搜索和比较各种英文词汇、短句、语法、单词解释等内容，并且可以统计出这个用语的变化形态，还可以分析使用频率和情境，堪比谷歌翻译。
5、CNKI翻译CNKI翻译助手是一款专业的学术翻译工具，由“中国知网”开发制作，汇集了从CNKI系列数据库中挖掘的大量常用词汇、专业术语、成语俚语及双语例句等，形成海量中英在线词典和双语平行语料库。
6、LingoesLingoes是一款简明易用的词典与文本翻译软件，支持全球超过80多种语言的词典查询、全文翻译、屏幕取词、划词翻译、例句搜索、网络释义和真人语音朗读功能。
7、有道词典有道词典是个神器，尤其是查词、划词、取词的方面特别突出，词库中有所有专业用语的补充包，可以让你瞬间翻译出各种专业的英文单词，从复杂的有机化合物，到稀奇古怪的动物名，哪里不会点哪里。
8、Copy Translator比较适用于即时翻译，内置了谷歌翻译、百度翻译、有道翻译、搜狗翻译、彩云翻译和腾讯翻译几种不同的翻译引擎，随意切换，总有一个适合你。
安卓开发英文参考文献(精选120个最新)
随着社会经济的发展以及科学技术的进步，智能手机以及个人电脑被广泛应用在人们的日常生产生活中。
安卓操作系统作为智能的操作系统，其具有高度的开放性，使得智能手机以及个人电脑具有较大的应用优势，下面是安卓开发英文参考文献，欢迎借鉴参考。
安卓开发英文参考文献一： [1]Haomin Song,Duanqing Xu. The Design and Development of a Full Range of Display System for 3D Images Based on AndroidSmartphone[P]. Proceedings of the International Conference on Education, Management, Commerce and Society,2015. [2]Iva Evry Robyansah. The Development of “Ayo Membaca” Android Application for Reading Assessment[P]. Proceedings of the 2nd International Conference on Education Innovation (ICEI 2018),2018. [3]Qingru Lu,Haiyan Xin,Hui Huang,Yunlong Geng. Design and Development of Multifunction Map Software Based on AndroidPlatform[P]. Proceedings of the 2015 International Conference on Electromechanical Control Technology and Transportation,2015. [4]Hongsheng Zhang. Research on Software Development and Test Environment Automation based on Android Platform[P]. Proceedings of the 3rd International Conference on Mechatronics Engineering and Information Technology (ICMEIT 2019),2019. [5]Yong-fei Ye,Ming-he Liu,Xiao Zhang,Xing-hua Sun,Nai-di Liu. Application and Research of Blended Teaching Model in Programming Courses --- Android Application Development Course as an Example[P]. Proceedings of the 3d International Conference on Applied Social Science Research,2016. [6]Xinge Li. The development of designated driving application based on Android platform and Ali cloud sever[P]. Proceedings of the 2016 2nd Workshop on Advanced Research and Technology in Industry Applications,2016. [7]Winda Dwi Fitria,Achmad Lutfi. Development Of Wind’s Maze Chemistry Game Based On Android As A Learning Media On Hydrocarbon Matter For Eleventh Grade Senior High School[P]. Proceedings of the Seminar Nasional Kimia - National Seminar on Chemistry (SNK2018),2018. [8]Fuling Li,Yong Li. Development of Mobile Security Guard Based on Android System[P]. Proceedings of the 2015 International Conference on Automation, Mechanical Control and Computational Engineering,2015. [9]Qinhua Lin. Mobile terminal 3D image reconstruction program development based on Android[P]. Proceedings of the 2015International Conference on Automation, Mechanical Control and Computational Engineering,2015. [10]Anan Sutisna,Elais Retnowati,Adi Irvansyah. Development of Peer Tutors Learning Media based on Android Application to Improve Learners Independence[P]. Proceedings of the 2nd International Conference on Educational Sciences (ICES 2018),2019. [11]Agus Ria Kumara,Caraka Putra Bhakti,BudiAstuti,Suwarjo,Muhammad Alfarizqi Nizamuddin Ghiffari,Fathia Irbati Ammattulloh. Development of Android Application based on Holland's Theory of Individual Student Planning[P]. Joint proceedings of the International Conference on Social Science and Character Educations (IcoSSCE 2018) and International Conference on Social Studies, Moral, and Character Education (ICSMC 2018),2019. [12]Suherman,Defri Ahmad,Meira Parma Dewi,Heru Maulana. Paper Development of Actuarial E-learning Based on AndroidApplications[P]. Proceedings of the 2nd International Conference on Mathematics and Mathematics Education 2018 (ICM2E 2018),2018. [13]Lan-Xin Zhu,Jia-Ming Zhang,Xiao-Li Rui,Xiao Liang. Research and Development of Android Client and Server Information Interaction Framework[P]. Proceedings of the 3rd International Conference on Wireless Communication and Sensor Networks (WCSN 2016),2016. [14]Hongxin Hu,Ming Cui. Development Scheme of Mobile Campus Information Integration Platform Based on Android[P]. isccca-13,2013. [15]Junliang Wu,Liqing Mao. Study on Research Development and Application of Urban Logistics Platform Based on Android[P]. Proceedings of the 2018 6th International Conference on Machinery, Materials and Computing Technology (ICMMCT 2018),2018. [16]Xiafu Pan. Anti-addiction System Development Based on Android Smartphone[P]. Proceedings of the 2016 3rd International Conference on Materials Engineering, Manufacturing Technology and Control,2016. [17]Xiufeng Shao,Xuemei Liu,Lingling Zhao. Development and Reform of Android Mobile Application Development Curriculum[P]. Proceedings of the 2016 International Conference on Applied Mathematics, Simulation and Modelling,2016. [18]Hongchang Ke,Degang Kong. Research on Course Integration of Mobile Internet Device Programming (Android Program Development)[P]. Proceedings of the 2018 8th International Conference on Mechatronics, Computer and Education Informationization (MCEI 2018),2018. [19]Xin Xin Xie,Wen Zhun Huang. Research and Development of the Android Framework Smart Watches from the Data Security Point ofView[P]. Proceedings of the 2nd International Conference on Advances in Mechanical Engineering and Industrial Informatics (AMEII2016),2016. [20]Abdel-All Marwa,Angell Blake,Jan Stephen,Praveen D,Joshi Rohina. The development of an Android platform to undertake a discrete choice experiment in a low resource setting.[J]. Archivesof public health=Archives belges de sante publique,2019,77. [21]Abdul Mutholib,Teddy S Gunawan,Jalel Chebil,Mira Kartiwi. Development of Portable Automatic Number Plate Recognition System on Android Mobile Phone[J]. IOP Conference Series: Materials Science and Engineering,2013,53(1). [22]Iliana Mohd Ali,Nooraida Samsudin. The Design and Development of BMI Calc Android Application[J]. IOP Conference Series: Materials Science and Engineering,2016,160(1). [23]Ashutosh Gupta,Tathagata Ghosh,Pradeep Kumar,Shruthi. S Bhawna. Development of Android Based Powered Intelligent Wheelchair for Quadriplegic Persons[J]. IOP Conference Series: Materials Science and Engineering,2017,225(1). [24]Ashutosh Gupta,Pradeep Kumar,Tathagata Ghosh,Shruthi. S Bhawna. Development of Android based Smart Power Saving System[J]. IOP Conference Series: Materials Science andEngineering,2017,225(1). [25]P Sihombing,Y M Siregar,J T Tarigan,I Jaya,A Turnip. Development of building security integration system using sensors, microcontroller and GPS (Global Positioning System) based android smartphone[J]. Journal of Physics: Conference Series,2018,978(1). [26]R F Rahmat,O R Fahrani,S Purnamawati,M F Pasha. The development of indonesian traditional bekel game in androidplatform[J]. Journal of Physics: Conference Series,2018,978(1). [27]P Hendikawati,R Arifudin,M Z Zahid. Development of computer-assisted instruction application for statistical data analysis android platform as learning resource[J]. Journal of Physics: Conference Series,2018,983(1). [28]Hartatik,F Febriyanto,H Munawaroh. Development ofApplications about Hazards and Preventions of Drug Based OnAndroid[J]. IOP Conference Series: Materials Science and Engineering,2018,333(1). [29]R Widyastuti,H Soegiyanto,Y Yusup. The Development of Geo Smart Based Android for Geography Learning Media on Hydrosphere Material and Its Impact towards Life on Earth[J]. IOP Conference Series: Earth and Environmental Science,2018,145(1). [30]Mohar Kassim,Ahmad Mujahid Ahmad Zaidi,Rahmat Sholihin Mokhtar. Development of Android Application for Measuring Cardiovascular Endurance Fitness for Military Cadet Officers[J]. Journal of Physics: Conference Series,2018,1020(1). 安卓开发英文参考文献二： [31]Abdul Rahman,Mulbar Usman,Ansari Saleh Ahmar. The Development of Android and Web-based Logical Thinking Measurement Tools as an Alternative Solution for Research Instruments[J]. Journal of Physics: Conference Series,2018,1028(1). [32]M. Reza Dwi Saputra,Heru Kuswanto. Development of Physics Mobile (Android) Learning Themed Indonesian Culture Hombo Batu onthe Topic of Newton’s Law and Parabolic Motion for Class XSMA/MA[J]. Journal of Physics: Conference Series,2018,1097(1). [33]M Yusro,Rikawarastuti. Development of Smart Infusion Control and Monitoring System (SICoMS) Based Web and Android Application[J]. IOP Conference Series: Materials Science andEngineering,2018,434(1). [34]Daniel Patricko Hutabarat,Santoso Budijono,Robby Saleh. Development of home security system using ESP8266 and android smartphone as the monitoring tool[J]. IOP Conference Series: Earth and Environmental Science,2018,195(1). [35]C M Zhang,L S Zhang,T Zhang,S T Zhang. Development of a machine tool auxiliary machining system based on android phone[J]. IOP Conference Series: Materials Science andEngineering,2019,504(1). [36]Ryan Ari Setyawan,Selo,Bimo Sunarfri Hantono. Effect of the Application of TEA Algorithm on the Development of Secure Phone Application Android Smartphones[J]. Journal of Physics: Conference Series,2019,1175(1). [37]M Basyir,W Mellyssa,S Suryati,M Munawar. Receiver Apps Development for Emergency Reporting System Based on AndroidPlatform[J]. IOP Conference Series: Materials Science and Engineering,2019,536(1). [38]B Angrian,T R Sahroni. Development of vendor management ande-Procurement systems using android platform[J]. IOP Conference Series: Materials Science and Engineering,2019,528(1). [39]O F Irianti,A Qohar. Development of Android BasedInstructional Media of Algebraic Tiles for Quadratic Equation[J]. Journal of Physics: Conference Series,2019,1227(1). [40]Fita Permata Sari,L. Ratnaningtyas,Insih Wilujeng,Jumadi,Heru Kuswanto. Development of Android Comics media on Thermodynamic Experiment to Map the Science Process Skill for Senior HighSchool[J]. Journal of Physics: Conference Series,2019,1233(1). [41]Puji Iman Nursuhud,Danis Alif Oktavia,Mas Aji Kurniawan,Insih Wilujeng,Jumadi,Heru Kuswanto. Multimedia Learning ModulesDevelopment based on Android Assisted in Light DiffractionConcept[J]. Journal of Physics: Conference Series,2019,1233(1). [42]Dadan Rosana,Didik Setyawarno,Wita Setyaningsih. 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Design and Development of Mobile Learning Platform Based on Android for College Physics Experiment Courses[P]. 3rd International Conference on Electronic Information Technology and Intellectualization (ICEITI 2017),2017. [79]Qiang CHEN,Jia-Jia WU. Research on Course of Integrating Android Development and Embedded Software[P]. 3rd International Conference on Education and Social Development (ICESD 2017),2017. [80]Alexander Chatzigeorgiou,Tryfon L. Theodorou,George E. Violettas,Stelios Xinogalos. Blending an Android development course with software engineering concepts[J]. Education and Information Technologies,2016,21(6). [81]Yasushige Ishikawa,Craig Smith,Mutsumi Kondo,IchiroAkano,Kate Maher,Norihisa Wada. Development and Use of an EFL Reading Practice Application for an Android Tablet Computer[J]. International Journal of Mobile and Blended Learning(IJMBL),2014,6(3). [82]Liguo Yu. From Android Bug Reports to Android Bug Handling Process: An Empirical Study of Open-Source Development[J]. International Journal of Open Source Software and Processes (IJOSSP),2016,7(4). [83]Nurul Farhana Jumaat,Zaidatun Tasir. Integrating Project Based Learning Environment into the Design and Development of Mobile Apps for Learning 2D-Animation[J]. Procedia - Social and Behavioral Sciences,2013,103. [84]Chan Daraly Chin,Watit Benjapolakul. NFC-enabled Android Smartphone Application Development to Hide 4 Digits Passcode for Access Control System[J]. Procedia Computer Science,2016,86. [85]Haolun Xu,Jinling Zhao,YaLi Li,ChangQuan Xu. The development of SHS-SWTHS designing software based on windows and android mobile device platforms[J]. Renewable Energy,2015,84. [86]Agnes Kurniati,Nadia,Fidelson Tanzil,Fredy Purnomo. Game Development “Tales of Mamochi” with Role Playing Game Concept Based on Android[J]. Procedia Computer Science,2015,59. [87]Tom Gaffney. 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Android基础知识之API等级介绍
Android基础知识之API等级介绍:可以让开发者通过⼀个表⽰API级别的整数来描述程序在android平台上的兼容性，系统会将与系统本⾝提供的API级别与应⽤指定的API级别⽐较。
尽管他有这个名字，但是该元素只是⽤来指定API级别，并不是⽤来指定SDK或者android平台的版本号。
API级别也是⼀个整数，但是你不能根据android版本号来追溯API级别(例如，它并不等同于主版本号或是主版本与次版本号的和)。
同样，请阅读⽂档.::Google Play会过滤应⽤对⽤户的可见性，⽤户只能看见和下载那些与⽤户设备兼容的⼀些应⽤。
过滤应⽤的⼀种⽅式就是通过Android版本的兼容性。
为此，Google Play会检查每个应⽤的Manifest⽂件标记的属性来构建版本兼容性范围，然后会根据它与⽤户Android系统的API级别的⽐对来决定隐藏或者显⽰该应⽤。
可以参考.属性：:android:minSdkVersion::⼀个整数来指定程序可以运⾏的最⼩版本。
如果⽤户系统的API级别⼩于该属性指定的值，系统将会阻⽌⽤户来安装此应⽤。
你应该⼀直声明这个属性。
* 注意* ：如果没有显⽰的声明该属性，系统指定⼀个默认值1，表明你的程序兼容Android系统的所有版本。
如果应⽤并不是兼容所有的版本的android系统(举例来说，应⽤⽤到了API3 才引⽤的API)，⽽且你没有声明minSdkVersion属性，当应⽤安装到API的级别⼩于3的系统上且试图访问不可⽤的API时，系统将会异常终⽌。
有鉴于此，请确定，应⽤已显式声明 minSdkVersion属性。
:android:targetSdkVersion::⼀个整数⽤来指定应⽤⽬标的API级别。
如果没有设置,默认值等于minSdkVersion所给的值。
::该值⽤来告诉系统应⽤已经在⽬标版本上进⾏测试以及系统可以不启⽤任何兼容性⾏为来维持你的应⽤的向前兼容性。
基于Android平台的多语种文字识别翻译APP
基于Android平台的多语种文字识别翻译APP
张璘;唐瑞寒
【期刊名称】《厦门理工学院学报》
【年(卷),期】2017(25)5
【摘要】集成中、英、日、韩、法、西班牙6种世界主要语种,通过jTessBoxEditor OCR开发引擎自主生成训练文字库,利用Tesseract识别引擎对文字进行识别,并将已识别文字送入第三方翻译接口进行目标语种翻译,开发了一款基于Android平台的集成了多语种文字的拍照识别翻译软件APP.通过景区样本实测结果验证,该APP的文字识别率可达93%,实现有效翻译,达到市场准入水平.
【总页数】6页(P61-66)
【作者】张璘;唐瑞寒
【作者单位】厦门理工学院光电与通信工程学院, 福建厦门361024;厦门理工学院光电与通信工程学院, 福建厦门361024
【正文语种】中文
【中图分类】TP391.43
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2.基于文字识别与页面布局的APP控件识别算法 [J], 丁世举;顾乃杰;黄章进;侯津
3.畅玩儿去多语种、便携翻译App推荐 [J],
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伟
5.基于多模态输入的多语种实时翻译软件设计与实现 [J], 权朝臣;邓长明;袁凌云因版权原因，仅展示原文概要，查看原文内容请购买。
安卓常见英文缩写的全拼
安卓常见英⽂缩写的全拼
1. Dalvik： Android特有的虚拟机,和JVM不同,Dalvik虚拟机⾮常适合在移动终端上使⽤!
2. AVD： (android virtual machine):安卓虚拟设备,就是安卓的模拟器
3. ADT： (android development tools)安卓开发⼯具
4. SDK：(software development kit)软件开发⼯具包,就是安卓系统,平台架构等的⼯具集合,如adb.exe
5. DDMS：(dalvik debug monitor service)安卓调试⼯具
6. adb：安卓调试桥,在sdk的platform-tools⽬录下,功能很多,命令⾏必备
7. DX⼯具：将.class转换成.dex⽂件
8. AAPT：(android asset packing tool),安卓资源打包⼯具
9. R.java⽂件：由aapt⼯具根据App中的资源⽂件⾃动⽣成,可以理解为资源字典
10. AndroidManifest.xml：app包名 + 组件声明 + 程序兼容的最低版本 + 所需权限等程序的配置⽂件。
android中文API合集(50篇)android中文翻译组
Android中文API合集（50篇）Android中文翻译组关于API文档(Reference)是Android开发的基础，三年来(2007-2010)官方仍未出中文版的API，Android中文翻译组聚一批从事Android开发人员、论坛版主、大学生、研究生等利用业余时间对Android的API进行翻译，人数从1人到80+人不断壮大，发表的译文从1篇到50篇不断增多，为的只是多一份Android中文资料，欢迎更多朋友的加入，联系我们：QQ：36408253 Gtalk：over140@欢迎大家访问翻译组在淘蝌蚪上搭建的项目：/project/view/404/（cnAndroid），可使用SVN客户端匿名下载：/svn/cnAndroid，在这里可以查看翻译组当前的最新的进度和翻译稿，也可以直接向我们提问。
关于翻译组的更多介绍，请看这里。
章节结构继承关系public final class Manifest extends Objectng.Object android.Manifest内部类class Manifest.permission权限class Manifest.permission_group权限组构造函数public Manifest ()构造函数补充文章精选android Manifest.xml选项Manifest.permission结构继承关系public static final class Manifest.permission extends Objectng.Objectandroid. Manifest.permission常量结构继承关系public static final class Manifest.permission_group extends Objectng.Objectandroid. Manifest.permission_group常量结构public abstract class AccessibilityService extends Serviceng.Objectandroid.content.Contextandroid.content.ContextWrapperandroid.app.Serviceandroid.accessibilityservice.Accessibil ityService类概述当AccessibilityEvent事件被启动后AccessibilityService 会接收回调函数运行于后台，这些事件指的是在用户接口间的状态转换，比如,焦点变化，按钮被点击等。
安卓系统与IOS系统比较—英文文献翻译外文翻译
ESEP 2011: 9-10 December 2011, SingaporeAn Analysis and Comparison of Open and Closed MobilePlatformsAndroid vs. iPhoneYinglu ZOUa, , Hao WU b, Jianxin HUANG a,ba Information Engineering College,7 JianXue Road, JinShui District, ZhengZhou,450001, ChinaAbstractWith the release of Android 2.2 Froyo and iPhone 4, the war between open and closed mobile platforms tends to befiercer. Being the representatives of the two parties, Froyo and iOS 4 are quite different at system framework, newfeature, application market and integration model. According to the company spirits of Google and Apple, we do some analyses and comparisons of the above points, explain the differences of Android and iPhone from the shallower to the deeper, then conclude the characteristics of open and closed mobile platforms, aiming at providing an objective reference for researchers of mobile platforms, helping them see clearer into mobile industry. As a result,both Froyo and iOS 4 have their advantages and disadvantages, still they are far from being perfect, there‟s room forfurther improvement.Keywords: Android；iPhone；Froyo；iOS 4；smart phone；mobile platform1. IntroductionIn recent years, the popularity of smart phone kept going up. More and more smart phones are sold anda lot of people are embracing them. Smart phones brought great convenience to users, as well created opportunities for smart phone researchers. That‟s to say, the wide spread of smart phones benefited both sides. At the same time, developing of smart phone OS becomes one of the smartest industry. To be a smart phone OS, the system should: 1. Provide services like a PC. 2. Work with a GPU for better visual effects. 3. Allow the user to surf on Internet freely. And apparently, there‟re also some weaknesses:1.Limited batte ry. 2. Poor CPU performance against PC CPU. 3. Small storage. 4. The use of RAM may leads to loss of data when the phone runs out of batteryNow the 2 giants of smart phone OS are Android and iPhone OS. On one side, Android is based on Linux kernel and Dalvik virtual machine, and it is open sourced. The upper layer of Android is Java based,allowing developers to develop Android applications with Google SDK and sell their software in Android Market. On theother side, iPhone OS, which bases on Unix kernel and Darwin model but is closed sourced,evolves from Mac OS X and is the default OS of iPhone, iPod Touch and iPad. Objective C based software can run in iPhone OS, and just like Android, you can develop your own iPhone applications and upload them onto Apple‟s …App Store‟ for sale [1] [2] [3] [4].By comparing the latest Android and iPhone OS, Android 2.2 Froyo and iOS 4, we can take a glimpse at the main feature of open and closed smart phone OSs. While the 2 OSs are designed in rather different mentality an d functionality, it‟s a little early to tell which one is better.2. Smart Phone OS2.1. AndroidThe system architecture of Android consists of 5 layers, which are Linux Kernel, Android Runtime, Libraries, Application Framework and Applications, from bottom to top.Android provides core services like security, memory management, process management, network stack and drivers, basing on Linux 2.6. Being the abstract layer between software and hardware, the layer of Linux Kernel hides the implementing details of hardware and provides integrated services for upper layer.Dalvik virtual machine and Java core libraries are included in the layer of Android Runtime, providing most functions in Java core libraries.The layer of Libraries contains a class of C/C++ libraries for Android components. Those libraries are integrated by the layer of Application Framework and then provided to developers.The layer of Application Framework provides all kinds of modules for program initialization to simplify the use of components, allowing developers do whatever they want and provide services for other softwares, under the limitation of security, of course.Mainstream applications are located in the layer of Application, including e-mail, SMS, calendar, Google map, Web browser and contacts. Users interact directly with this layer [1] [2].The latest version of Android, Android 2.2 Froyo, puts on some new features. They are: 1. Support Flash 10.1, enables user to watch flash on the phone. 2. V8 JavaScript engine in web browser leads to faster Internet data transportation. 3. Big advance in network sharing. You can use the phone as a 3G NIC,or convert 3G signalto Wi-Fi. 4. Automatically software update. 5. Softwares can be setup in SD card to extend file storages.2.2. iPhoneiPhone OS is consist of 4 abstract layers: Core OS, Core Service, Media and Cocoa Touch respectively.Layers of Core OS and Core Service are designed in C language to handle core system services, enabling developers to perform file access, sockets calling and data handling. CFNetwork and SQLite are also parts of these 2 layers.The layer of Media, according to its name, this layer is used to control video and audio, as well handle 2D and 3D images. The Open GL-ES Quratz part of the layer is coded with C language, while the part of Core-Audio and Core-Animation is Objective C based.The layer of Cocoa Touch builds a basic framework for all kinds of programs in iPhone. Most programs run in Cocoa Touch layer, and it‟s surely Objective C based [3] [4].The latest iPhone OS is iOS 4. It includes the following new features: 1.Software classification. Thisfeature enables user to place sorted softwares into different documents, making it clearer to manage. 2. Email integration. One account is for all e-mails from different providers. 3. iBook, originally from iPad, is built in iOS. 4. A brand new Apple Game Center makes iPhone a tremendous entertainment platform.2.3. Android vs. iPhoneBeing the top 2 smart phone OSs, we‟re sure that both Android and iPhone have their own advantages and disadvantages. Now let‟s take a look at each of them, and see what unique feature they have.Android 2.2 Froyo fully support multitask, which means you can listen to music while writing blog. And iOS 4, officially announced to be …multitasked‟, is in fact a play of concept. Only a few of softwares which are authorized by Apple can run …simultaneously‟, whose principle is much easier that multitask:when an application is switched out, its current state is saved and then the system just closes it. And when it‟s switched in, we‟re back to the previous snapshot [5] [6] [7].During the publication of Android 2.2 Froyo, Google announced it has …the most fluent web browser‟,because the use of V8 JavaScript engine. V8 is a brand new engine, designed for running big size JavaScript application. In some kind of tests, V8is much faster than JScript from Internet Explorer, SpiderMonkey from Firefox and JavaScriptCore from Safari. It all owe to 3 key parts of V8, they‟re fast attribute access, dynamic code generation, effective trash cleaning.2.3.1. Fast Attribute AccessJavaScript is a kind of dynamic language, which means attributes can be added or deleted at runtime, and they‟re frequently changed. Most JavaScript engines use a dictionary style structure to store the attributes of an object, so it requires a whole dictionary search to find the position of attributes in memory.It‟s quite inefficient and it‟s slower than Java and Smalltalk.To solve this problem, V8 discarded dynamic search and realized it in a different way: Create hidden classes for objects dynamically. In JavaScript, every time when we‟re adding a new attribute to an object,we create a subclass with the new attribute from a hidden class as the super class. It‟s a recursive course and the above performance happens only once when we first do this. Later we just use the previous hidden subclass when we‟re in the same situation. So there‟s no need to repeat operation and create a dictionary. This leads to the save of time and energy, as well make it easier for the implementation of class optimization and inner cache [4].2.3.2. Dynamic Code GenerationWhen JavaScript is running for the very first time, V8 translate it directly into local machine code, rather than explain it to bytecode. Attribute access is done by inner cache, which is often translated into instructions by V8 at runtime.When it comes to the code where certain object is accessed, V8 tries to find the current hidden class. Meanwhile, V8 assumes that all objects in the snippet are described by the same hidden class, so V8 willmodify corresponding inner cache to make the direct use of the hidden class more convenient. If thisassumption is correct, the access of attributes can be all done in only 1 instruction. Even if the predictionfails, inner cache is modified again by V8, which won‟t take too much time and resource. When one hidden class is shared by a lot of objects, the access speed can be close to most dynamic language access speed. Inner cache and hidden class, mixed with dynamic code and class optimization, improve the efficiency of JavaScript at a large scale [4].2.3.3. Effective Trash CleaningV8 does memory recycles automatically. To guarantee the speed of object distribution, as well cut the time of trash cleaning and clear fragment up, V8 willinterrupt the running application when performing trash cleaning. Mostly, only a small part of object stack is involved in trash cleaning cycle, so the interruption caused little. All location of objects and pointers are logged by V8, so the system won‟t take object for pointer and memory overflow is avoided [4].Besides …the most fluent web browser‟, Google collaborated with Adobe and Android 2.2 Froyo fully supports Flash. That‟s to say, not only flash media, but all flash web pages can display perfectly on Android. To the contrary, Apple turned down Adobe and take HTML5 as iPhone‟s web protocol, making it unable to show some flash based animation.Android 2.2 Froyo also leads the way in network sharing. Smart phone with Froyo can be connected toa PC as a 3G NIC, and can also conveniently convert 3G signal to Wi-Fi. iOS 4 can do the first too, butfailed to convert 3G to Wi-Fi.Video conference is both supported by Froyo and iOS 4, but the conditions are different. You can see aFroyo user via camera as long as you get a camera also. However, iOS 4 user can only do video talk toanother iOS 4 user, which is a big limitation.While Android is ascendant in network interaction, Apple is unique in its friendship and entertainment.The added feature of …software classification‟ enables user to place sorted softwares into differentdocuments, making it clearer to manage. What‟s more, there‟re hundreds of thousands applications inApp Store, meaning that iPhone can have up to hundreds of thousands functions. This is a ratherremarkable feature that Apple publicizes.And the most convincing point given by Apple, is that …Android looks exactly familiar with iPhone.‟Although it‟s just a subjective sense, the born of iPhone really brought big revolution to the phone industry, and the name …Apple‟ itself is a world famous brand [7] [8].3. Open and Closed platforms3.1. SDKThe most important part of every developing platform is SDK, enable 3rd party developers to make software for the platform. Usually, libraries, debug tools and emulators are included in SDK. Different platforms distribute their SDKs differently. Some SDK is complete free and open, while others are strictly limited.Developers of open platforms can get and modify part or all of the source code. Google and Linux are leaders of open platforms; they publicized the whole sourcecode of Android and Linux. The good point is that, platform owners can save a great amount of time and energy developing and maintaining the platform, because 3rd party developers will do this for them. With less money spent on development and maintenance, a relatively low price can attract more and more phone users.Contrarily, closed platforms lock their source code in the safety and forbid 3rd party accesses. Apple and Microsoft are the representatives of them, they are both closed sourced, but some differences do exists. 3rd party iPhone applications are restricted within narrow limits, for that Apple will look through every application which is uploaded onto …App Store‟, and a lot of applications are turned down.Microsoft don‟t check Windows applications at all, it all depends on the users themselves. You installed the mareware, you suffer the loss.3.2. Application MarketMarket is the medium between de velopers and users, hence it‟s very important. Some predicted that there will be more and more application markets while some don‟t think so. In current markets, both do exist. Some specify only one market for their products, while others sell their softwares in various markets.Softwares from Nokia, Microsoft and Linux Mobile are sold in every market. Developers of these platforms can release their own application in whatever markets, so markets have to compete with each other for a living. This is good for users. However, the lack of universal management may lead to mess and chaos, softwares that have the same functionality exist in different markets, which confuses users a lot.Correspondingly, sole markets claim that most applications should be sold in them. This kind of monopolization leads to no competitor. …App Store‟ and ‟Android Market‟ are deputy of sole markets. Normally, iPhone applications can only be found in …App Store‟, and Apple will check every one of them by itself. Good news is that every application in …App Store‟ is officially tested, it‟s safe; Bad news is that a lot of pretty good softwares are rejected for various reasons. And a big unofficial mechanism is built by hackers, that is …jailbreak‟ and …SIM unlock‟.…Jailbreak‟ is a process that allows iPad, iPhone and iPod Touch users to gain root access and unlock the operating system thus removing any limitations imposed upon them by Apple. Once jailbroken, iPhone users are able to download many extensions and themes previously unavailable through the App Store via installers such as Cydia. A jailbroken iPad, iPhone or iPod Touch is still able to use the App Store and iTunes [9].And a …SIM lock‟ is a capability built into GSM phones by mobile phonemanufacturers. Networkproviders use this capability to restrict the use of these phones to specific countries and network providers.Generally, phones can be locked to accept only SIM cards based on the International Mobile Subscriber Identity. …SIM unlock‟ make it possible to use a mobile phone without considering countries and networks specified by mobile phone manufacturers.However in Android, Google doesn‟t test every application at all, so although there‟s an official market for Android applications, you can still release your product anywhere you want. Considering security problems, Google banned the use of some components. Like …jailbreak‟ and …SIM unlock‟ in iPhone, …root‟ in Android gives users 100% control of their devices, along with some security risks. …Root‟ is a process that allows users of cellphones running the Android operating system to attain privileged control (known as "root access") within Android's Linux subsystem, similar to jailbreaking on Apple devices running the iOS operating system, overcoming limitations that the carriers and manufacturers put on such phones. Rooting makes it possible to use custom versions of the Android system such as CyanogenMod, supporting features unavailable in stock ROMs. It also allows for newer versions of Android not supplied by the original device manufacturer. In contrast to iOS jailbreaking, rooting is not needed to run applications not distributed by the official Android Market. It is needed however, when trying to access paid Android applications from countries which are not part of the paid applications market.3.3. IntegrationSome companies focus only on their core industry, i.e. develop an operating system and provide an environment for 3rd party development. Others not only do these, but manage the process of developing a software to publicizing it. Depending on the integration of platforms, we sort them to 4 kinds: full integration platform, market integration platform, device integration platform and no integration platform.The publicizing model of full integration platform is very strict. Its management ranges from device manufacturing to application release, whose representative is Apple. Apple‟s factory produces iPhone,Apple‟s …App Store‟ sells application, Apple‟s …iTunes‟ is the channel of Apple‟s resources. The whole process is under Apple‟s control.Market integration platforms commit themselves to developing and selling softwares. Google is one of them. Unlike apple, Google don‟t have a factory tomanufacture its own handsets, but only developed Android and set up …Android M arket‟ for Android applications. However, companies like Google definitely have the capability to produce its own devices. Google is in good relationship with HTC, who is the OEM of T-Mobile, O2 and Orange, etc.Device integration platforms produce their o wn handsets, but don‟t set up application markets. Forexample, RIM makes Blackberry, but there‟s no official application market for Blackberry. No integration platforms do few things. Microsoft neither makes mobile phones, nor sets up a market.What they do is only developing the operating system: Windows Phone 7.4. ConclusionRepresentatives of open and closed platforms, Android 2.2 Froyo and iOS 4 are both loved and hated.Great browsers are built into them, and their producers are both world famous revolutionary. Android leans to Internet experience, which comes down in one continuous line with Google. But currently, various versions of Android fill the market, and most companies in Open Handset Alliance tend to customize their own Android systems. These facts make Android lack of a general brand image, so people may feel confused and say …No‟ to Android. iPhone OS focuses more on entertainment and it‟s very friendly. But Apple is too cool to attract more customers: Diehard fans of Steve Jobs buy every product made by Apple, and people who dislike the style Apple do things may just sniffed at Apple.Besides, Android 2.2 Froyo succeeds the features of open platforms well. It‟s a …users only‟ platform, because users of Froyo can almost customize everything they want. And members of Open HandsetAlliance tend to provide more choices for users. And iOS 4, typically closed platform member, manages everything ranging from OS development to device manufacturing. It‟s a …consider for users‟ platform.To some extent, u sers of Android canonizes …free‟ and …open‟, what they care is if they have 100% management of their handsets, no matter whether the OS is called …Android‟ or …Another‟. Apple users are loyal to the brand; they would like to authorize Apple to make decisions for them. So although some iPhone users love physical keyboards, they bought iPhone. In other words, Android users think a lot of …open platform‟ rather than the brand Google; most iPhone users are follower of Apple, they love the …closed platforms‟ cre ated by Steve Jobs.Both Android and iPhone have their unique IDE, SDK and other characteristics. Believe it or not, no perfection exists in the world, so none of today‟s mobileplatforms fully meets the needs of users and researchers. The choice of platform boils down to the needs of users and researchers, this article should make the decision easier. Of course the content of this article is time sensitive; platforms will gradually meet the demands of consumers as new technologies emerging.References[1] Dave Mark, Jeff LaMarche. “Beginning iPhone 3 Development: Exploring the iPhone SDK”. 2009.[2] Erica Sadun. “The iPhone Developer‟s Cookbook: Building Application with the iPhone SDK”, 2009.[3] Ed Burnette. “Hello, Android: Introducing Google‟s Mobile De velopment Platform”, 2009.[4] W.Frank Ableson, Charlie Collins, Robi Sen. “Unlocking Android: A Developer‟s Guide”, 2010.[5] Hee- Yeon Cho, Choon- Sung Nam, Dong- Ryeol Shin. “A Comparison of Open and Closed Mobile Platforms”.International Conference on Electronics and Information Engineering, 2010.[6] Ryan C. McKeen, Finis R. Price III. “DROID v iPHONE”. ABA Journal, 2010.[7] Mies Ginny, Sullivan Mark. “iPhone 4 vs. Droid X: A Head-to-Head Comparison”. PC World, 2010.[8] Fleishman, Glenn. “More Options With Tomorrow's Cell Phones”. PC World, 2008.[9] Keller, Mike. “Jailbreaking Your iPhone: The Pros and Cons”. PC World, 2010.分析和比较开放和封闭的移动平台摘要随着Android 2.2 Froyo和iPhone 4版本的发布，开放式和封闭式的移动平台之间的战争愈演愈烈。
简易翻译器(Android应用使用Java开发)
简易翻译器（Android应用使用Java开发）一、引言在全球化的今天，语言交流变得越来越重要。
然而，不同的语言之间存在着障碍，这给人们的沟通带来了困扰。
为了解决这个问题，我们开发了一款简易翻译器应用，可以在Android手机上使用。
本文将介绍该应用的功能、设计理念和开发过程。
二、功能概述1. 多语言支持：简易翻译器支持多种语言翻译，包括但不限于英语、中文、法语、德语等常用语言。
2. 文本翻译：用户可以输入需要翻译的文本，应用会将其实时翻译成目标语言，并显示在界面上。
3. 语音翻译：用户可以使用语音输入功能，将语音转换为文本进行翻译，同时也可以将翻译结果以语音形式输出。
4. 离线翻译：对于一些常用的短语或句子，翻译器可以提供离线翻译功能，不需要网络连接即可完成翻译。
5. 历史记录：用户使用过的翻译结果会被保存在历史记录中，方便用户查找和管理。
三、设计理念1. 界面简洁直观：我们注重用户体验，将界面设计简洁直观，避免过多的复杂操作和干扰，使用户能够轻松地使用翻译器。
2. 强大的翻译引擎：我们选择使用业界知名的翻译引擎作为后台支持，以确保翻译结果的准确性和稳定性。
3. 数据保密与安全性：为了保护用户的隐私和个人信息安全，我们采用了严格的数据加密和权限管理措施。
四、开发过程1. 技术选型：基于Android平台的开发，我们选择使用Java语言进行开发，因为Java具有良好的跨平台性和开发效率。
2. 界面设计：我们参考了现有的翻译应用，在用户体验和交互设计方面进行了优化，确保用户可以直观地操作应用。
3. 数据处理：我们使用了第三方翻译引擎的API接口，通过调用接口实现文本和语音的翻译功能，同时使用本地存储管理历史记录。
4. 测试与优化：我们进行了严格的测试，发现并修复了一些潜在的问题和漏洞，以确保应用的稳定性和性能。
5. 发布与更新：经过多次迭代优化后，我们将翻译器应用发布到了Android应用商店，并定期更新以提供更好的功能和用户体验。
MT-Ⅲ级
MT-Ⅲ级概述MT-Ⅲ级是一种高级的机器翻译系统，其基于神经网络和机器学习技术，能够对输入的源语言文本进行自动翻译，输出目标语言文本。
MT-Ⅲ级具有高度的准确性和流畅性，广泛应用于各种翻译场景，包括跨语种翻译、专业领域翻译等。
特点1. 神经网络技术MT-Ⅲ级采用了先进的神经网络技术，包括深度学习和强化学习算法。
神经网络模型可以通过对大量的语料进行训练，自动学习源语言和目标语言之间的关系，从而更好地进行翻译。
神经网络模型可以处理更复杂的语言结构和语义信息，提升翻译的准确性和流畅性。
2. 自学习能力MT-Ⅲ级具有自学习能力，可以根据用户的反馈数据对自身进行优化。
用户使用MT-Ⅲ级进行翻译时，系统会自动记录用户的翻译选择和评价，通过机器学习算法进行分析和处理，从而改善翻译效果。
通过不断的优化和学习，MT-Ⅲ级可以逐步提升翻译质量，更好地满足用户的需求。
3. 多领域支持MT-Ⅲ级可以支持各种领域的翻译，包括通用领域、专业领域等。
MT-Ⅲ级在训练过程中充分考虑了不同领域的语言特点和翻译需求，通过对领域相关的语料进行训练，提高了在特定领域翻译的准确性和专业性。
无论是法律、医学、科技还是金融领域，MT-Ⅲ级都能够提供高质量的翻译结果。
4. 多语种支持MT-Ⅲ级支持多种语言的翻译，包括但不限于中文、英文、法文、德文、日文、韩文等。
MT-Ⅲ级可以根据用户的需求进行相应的配置和训练，以满足不同语种的翻译需求。
无论是中英文、中法文、中德文，还是其他语种之间的翻译，MT-Ⅲ级都能够提供高效准确的翻译服务。
使用场景MT-Ⅲ级广泛应用于各种翻译场景，包括但不限于：•商务会议：在跨国商务会议中，MT-Ⅲ级能够实时翻译与会人员的发言，提高沟通效率和准确性。
•跨语种沟通：在国际合作、交流活动中，MT-Ⅲ级可以帮助用户快速进行语言转换，方便双方交流。
•学术研究：在学术研究中，MT-Ⅲ级可以帮助研究人员阅读和分析其他语种的论文和资料，促进学术交流和合作。
JAVA学习过程论文中英文资料对照外文翻译文献
JAVA学习过程论文中英文资料对照外文翻译文献During my process of learning Java。
I have found that everyone has their own unique study method。
What works for one person may not work for another。
As I am studying Java independently。
I have not asked ___。
I have had to rely on my own ___ out。
While I cannot say whether this is the best method。
I can offer it as a reference for others.When I first started learning Java。
___ understanding of the language。
As I progressed。
I began to work on small projects to apply what I had learned.One of the biggest challenges I faced was understanding object-oriented programming。
___。
once I understood the basics。
everything else started to fall into place.___ practicing programming。
I also made sure to take breaks and give my brain time to rest。
I found that this helped me to ___.Overall。
my learning process has been a n of n。
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本科毕业设计(论文) 外文翻译（附外文原文）学院：信息科学与工程学院课题名称：基于腾讯微博开放平台的数字教学交流系统专业(方向)：计算机科学与技术班级： BCU09-4学生：周杰伦指导教师：方文山日期： 2013/4/19Android API级别当你开发你的Android应用程序时，了解该平台API变更管理的基本方法和概念是很有帮助的。
同样的，知道API级别标识以及该标识如何保障你的应用与实际硬件设备相兼容对于开发及后续的发布、维护都是有益的。
本节内容告诉你API级别的知识，以及它如何影响你开发和使用的应用。
关于如何使用“以API级别进行过滤”来使用API参考手册，从本文末尾的文档过滤(Filtering the documentation)中可以得到更多信息。
API级别是什么？API级别是一个整数值，它唯一标识了一个具体版本的Android平台，及其框架的API的版本。
Android平台提供了一套框架API，使得应用程序可以与系统底层进行交互。
该框架API由以下模块组成：∙一组核心的包和类∙清单(manifest)文件的XML元素和属性声明∙资源文件的XML元素和属性声明及访问形式∙各类意图(Intents)∙应用程序可以请求的各类授权，以及系统中包含的授权执行每个Android平台的后续版本会包括它提供的更新的Android应用程序框架的API。
该框架的API的更新设计，使高版本的API与早期版本兼容。
也就是说，在新版本API中大多数都是新增功能，和引进新的或替代的功能。
作为API的部分升级，老的替换的部分已过时，但不会从新版本中删除，使得已有的应用程序仍然可以使用它们。
在极少数情况下，旧版本API的部分可能被修改或删除，通常这种变化是为了保障API的稳定性及应用程序或系统的安全。
所有其他早期版本的API将不做修改的保留。
一个Android平台提供的框架API，被指定一个整数标识符，称为“API级别”。
每一个版本的Android平台只支持有一个API级别，虽然该支持是隐含地包括了所有早期的API级别（一直到API级别1级）。
Android平台的最初版本提供的框架API级别是1级，随后的版本依次递增。
下表说明了具体平台版本和支持的API级别的对应关系。
在Android中使用API级别API级别标识为保证用户和应用程序开发者的最佳体验，起了关键作用：∙它让Android平台可以描述它支持的框架API的最高版本∙它让应用程序可以描述它需要的框架API版本∙它使得系统可以在硬件设备上安装应用程序时能够检查版本是否匹配，使得版本不兼容的应用程序不会被错误安装在设备之上.每个版本的Android平台都在其内部存储了自己的API级别标识。
应用程序可以用框架API提供的清单文件元素— <uses-sdk> 来描述该应用程序可以运行的最小和最大API级别，以及应用程序开发者设计期望运行的平台版本。
三种属性分别描述如下:∙android:minSdkVersion—指明该应用程序可以运行的API最低版本。
默认是“1”。
∙android:targetSdkVersion—指明该应用程序设计时期望运行的目标API版本。
在某些情况下，这允许应用程序使用目标API级别下定义的清单元素或行为，而不是只限于使用最低API级别定义的内容。
∙android:maxSdkVersion—指明该应用程序可以运行的最高API级别。
重要声明:使用该属性之前请阅读<uses-sdk>文档。
比如，要指明一个应用程序能够运行的最低API级别，应当在该应用程序的清单文件的<uses-sdk>元素中加入android:minSdkVersion属性。
android:minSdkVersion的值是一个正整数，对应的是该应用程序能够运行的最低平台的API级别标识。
用户尝试安装一个应用程序，或者在系统升级后重验证应用程序的时候，Android系统首先会检查应用程序的清单文件中的<uses-sdk>属性，将其与系统内部API级别对比。
系统只有在满足下列情况时才允许进行应用程序安装：∙如果声明了android:minSdkVersion属性，其属性值必须小于或等于该系统的API 级别对应的整数值。
如果未声明，系统会默认该应用程序运行需要的最低API级别是1。
∙如果声明了android:maxSdkVersion属性，其属性值必须等于或大于该系统的API 级对应的整数值。
如果未声明，系统会默认该应用程序没有最高API级别限制。
请通过阅读文档<uses-sdk>以获得系统如何处理该属性的更多信息。
应用程序清单文件中声明该属性后，<uses-sdk>元素看起来应类似于下面的例子：这样做的主要原因是，应用程序会通过android:miniSdkVersion声明的API级别来告知系统——该应用程序使用的API是指定引入的API级别。
假如没有这种属性声明，一个应用程序如果因为某些不知名的原因被安装在低级别API系统之上，那么该应用程序会在运行时因为尝试访问不存在的API而崩溃。
为此，Android 系统通过不允许应用程序被安装在不满足其最低API级别要求的目标硬件上来防止此类结果发生。
例如，android.appwidget类包是在API级别3中开始引入的。
如果一个应用程序使用了这个API，就必须通过指明android:minSdkVersion属性为3来声明运行的最低要求。
于是，该应用程序就可以在Android 1.5（API级别3级）、Android1.6 (API级别4级)等平台上安装，但是在Android 1.1 (API级别2级)和 Android1.0 平台(API级别1级)上却是无法安装的。
欲知关于如何声明应用程序API级别需求的更多信息，请阅读文档中关于清单文件的<uses-sdk>章节。
开发者需要考虑的内容本节属于应用程序开发者需要了解的内容。
应用程序的向前兼容性Android应用程序一般向前兼容于Android平台的新版本。
这是因为几乎所有的框架API变更都是添加性质的，一个以某种版本的API 开发的应用程序是向前兼容与后续Android系统及高版本API。
应用程序应当可以运行于高版本的平台，除非使用了未来因某种原因移除的API。
向前兼容性的特性如此重要，是因为很多的Android驱动的设备能够使用OTA远程下载技术进行系统更新。
用户开始时能够很好的安装和使用你开发的应用程序，后来进行了OTA升级到新版本的Android平台。
一旦升级完毕，你的应用程序将运行在一个新的版本环境下，而这个环境应当包含了你的应用程序所需的API和系统功能。
某些情况下，API背后的变化，例如系统底层的变化，可能会影响到你的应用程序运行在新的环境下。
为此，作为应用程序开发人员，应当了解应用程序在不同系统环境下将会有如何的外观和行为。
Android SDK包含了多个平台版本，开发人员可以下载下来，用于测试自己的应用程序在不同版本下的运行情况。
每个版本的平台都提供了兼容的系统镜像，你可以将应用程序运行在对应的Android虚拟设备（模拟器）上进行测试。
应用程序的向后兼容性Android应用程序不一定向后兼容于那些比这些应用程序开发环境低的平台环境。
Android平台的每个新版本包含了新的框架API，例如新的平台功能，或者替代部分已有的API。
应用程序在新平台上可以访问这些新的API，就像之前提到的，在后续更新的版本中，这些新功能API也是可以继续使用。
相反的，因为早期版本的平台不会包含新的API功能，使用了新API的应用程序在那些旧平台上是无法运行的。
虽然一个Android平台设备不太可能降级到以前的版本，但是需要了解的是：实际生活中可能会有很多设备运行的是较旧的平台版本。
即使在设备接收到OTA 远程下载升级，有些人仍然可能会滞后甚至可能不会收到更新。
平台版本和API级别的选择当你开发应用程序时，你需要选择一个平台用于编译该应用程序。
通常，你应该在你的应用程序可以支持的最低版本的平台上进行编译。
你可以通过寻找最低的可以支持你的应用程序编译的平台方式来决定你将会支持的最低平台版本。
一旦你确定了支持的最低版本后，你就可以创建对应版本的AVD模拟器来全面测试你的应用程序。
你需要注意的是不要忘记在应用程序清单文件中申明android:minSdkVersion属性，并赋上正确的API级别标识。
声明最低API级别如果你开发的应用程序使用了最新平台上引入的API或平台特性，你就需要将android:minSdkVersion属性赋最新平台的API级别标识。
这将保证用户只能在他们的设备与你的应用程序平台版本兼容情况下安装。
反过来说，这样能够保证你的应用程序在他们的设备上表现正常。
如果你用了最新的API或平台特性，但是没有申明android:minSdkVersion属性，那么你的应用程序在最新平台上运行是没有稳定，但是在早期版本的平台上是会出错的。
在后一种情况，应用程序在尝试访问旧平台上不存在的API时会崩溃。
针对高版本的API级别测试编译完你的应用程序，你应当在支持的最低版本平台上详细测试应用程序的表现。
可以通过创建对应平台的AVD模拟器进行测试。
此外，要保证向前兼容性，你应当在你的应用程序可能运行的更高平台版本上进行运行和测试。
Android SDK包含了多个平台版本供开发者使用，其中包括了最新的版本，并且提供了升级工具使得开发者可以获取其他的版本。
要使用升级工具，可以通过Android命令行方式，该工具位于<sdk>/tools路径下。
你可以用敲入android指令运行该升级工具，而不用指定任何参数。
你也可以简单地通过双击Windows下的android.bat或OS X/Linux下的android文件来启动升级工具。
在ADT工具界面，你可以通过菜单的Window > Android SDK and AVD Manager来访问升级工具。
要想将你的应用程序在不同平台版本的模拟器上运行，需要创建对应的AVD 设备。
关于AVD的更多信息，请参见Creating and Managing Virtual Devices。
如果你用物理设备进行测试，确保清楚运行的具体平台版本。
通过本文开始部分的映射表格可以知道平台版本对应的API级别标识。
使用临时的API级别某些情况下，有可能会发布“早期预览(Early Look)”版的Android 平台SDK。
在此平台版本上开发使用的API将不会是最终发布版，平台的API级别标识数字就不会指定。