Android之Service学习总结

目录第十五课：Service学习(1) (1)1.1 什么是Service服务（例如，音乐播放器；下载链接 (1)1.2 Service和Thread（什么时候使用线程，什么时候使用服务 (1)1.3调用Service的方式startService()；bindService() (2)1.4通过startService()调用Service (2)1.4.1编写类继承Service或其子类 (2)1.4.2 复写方法onStartCommand() onBind() onCreate() onDestroy() (5)1.4.3在manifest文件中声服务<service android:name=".Service" /> (5)1.4.4 启动服务StartService (5)1.4.5关闭服务StopService (5)1.5 MainActivity.java (5)1.6 ExampleService.java (7)1.7 Main.xml (8)1.8 AndroidManifest.java (8)Android之Service学习总结我们的windows操作系统也是有服务的。

开始，运行：services.msc1.1 什么是Service服务（例如，音乐播放器；下载链接A Service is an application component应用程序组件that can perform long-running耗时的1.2 Service和Thread（什么时候使用线程，什么时候使用服务Dev Guide ServicesShould you use a service or a thread?A service is simply a component that can run in the background even when the user is not interacting with your application. Thus, you should create a service only if that is what you need.执行service，长的耗时操作，并且不需要和用户进行交互。

但是如果需要和用户进行交互时，我们要创建的是线程thread，而不是service，比如：我们需要在Activity中播放一段音乐，此时要使用线程。

If you need to perform work outside your main thread, but only while the user is interacting with your application, then you should probably instead create a new thread and not a service. For example, if you want to play some music, but only while your activity is running, you might create a thread in onCreate(), start running it in onStart(), then stop it in onStop(). Also consider using AsyncTask or HandlerThread, instead of the traditional Thread class. Seethe Processes and Threading document for more information about threads.Remember that if you do use a service, it still runs in your application's main thread by default, so you should still create a new thread within the service if it performs intensive or blocking operations.1.3调用Service的方式startService()；bindService()❿StartedstartService()：调用者（Activity）和服务之间没有联系，即使调用者退出了，服务仍然进行：点击btnStartService按钮，执行[onCreate()-->on Start()-->startService()-点击btnStopService onDestory()]❿Bound绑定bindService()：调用者和服务绑在一起，调用者一旦退出服务也就终止[onCreate()-->on Bind()-->onUnbind()-->onDestory()]1.4通过startService()调用Service1.4.1编写类继承Service或其子类ExampleService.java，视频中提供了一种方法创建类快捷方式：右击，选，————>classExampleService.java创建类快捷方式：右击，选，————>class package com.szy.service;import android.app.Service;import android.content.Intent;import android.os.IBinder;import android.util.Log;public class ExampleService extends Service{private static final String TAG="ExampleService";@Overridepublic void onCreate(){Log.i(TAG, "ExampleService-->onCreate");super.onCreate();System.out.println("oncreate");}1.4.2 复写方法 onStartCommand() onBind() onCreate() onDestroy()onStartCommand() onBind() onCreate() onDestroy()1.4.3在manifest文件中声服务<service android:name=".Service" /><service android:name=".Service" />1.4.4 启动服务StartService1.4.5关闭服务StopService1.5 MainActivity.javapackage com.szy.service;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity{private Button btnStartService;private Button btnStopService;@Overridepublic void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(yout.main);btnStartService = (Button) findViewById(R.id.btnStartService);btnStopService = (Button) findViewById(R.id.btnStopService);btnStartService.setOnClickListener(listener);btnStopService.setOnClickListener(listener);}private OnClickListener listener=new OnClickListener(){@Overridepublic void onClick(View v){Intent intent=new Intent(MainActivity.this, ExampleService.class);switch (v.getId()){case R.id.btnStartService:start Service(intent); //创建服务break;case R.id.btnStopService:stop Service(intent); //终止服务break;default:break;}}};}1.6 ExampleService.java创建类快捷方式：右击，选，————>class package com.szy.service;import android.app.Service;import android.content.Intent;import android.os.IBinder;import android.util.Log;public class ExampleService extends Service{private static final String TAG="ExampleService";@Overridepublic void onCreate(){Log.i(TAG, "ExampleService-->onCreate");super.onCreate();System.out.println("oncreate");}@Overridepublic void onStart(Intent intent, int startId){// TODO Auto-generated method stubsuper.onStart(intent, startId);System.out.println("onstart");}@Overridepublic void onDestroy(){Log.i(TAG, "ExampleService-->onDestroy"); System.out.println("ondestroy");super.onDestroy();}@Overridepublic int onStartCommand(Intent intent, int flags, int startId){Log.i(TAG, "ExampleService-->onStartCommand");System.out.println("onstartcommand");return START_NOT_STICKY;}@Overridepublic IBinder onBind(Intent intent){System.out.println("onbind");return null;}}1.7 Main.xml<?xml version="1.0"encoding="utf-8"?><LinearLayoutxmlns:android="/apk/res/android"android:orientation="vertical"android:layout_width="fill_parent"android:layout_height="fill_parent"><Buttonandroid:id="@+id/btnStartService"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Start Service"/><Buttonandroid:id="@+id/btnStopService"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Stop Service"/></LinearLayout>1.8 AndroidManifest.java<?xml version="1.0"encoding="utf-8"?><manifest xmlns:android="/apk/res/android"package="com.szy.service"android:versionCode="1"android:versionName="1.0"><uses-sdk android:minSdkVersion="8"/><application android:icon="@drawable/icon"android:label="@string/app_name"><activity android:name=".MainActivity"android:label="@string/app_name"><intent-filter><action android:name="android.intent.action.MAIN"/><categoryandroid:name="UNCHER"/></intent-filter></activity><service android:name=".ExampleService"/></application></manifest>。