Windows Phone 8 的文件和存储

WP8的文件和存储内容预告：∙特殊的文件夹（Shared/Media，Shared/ShellContent，Shared/Transfer）∙用ISET浏览本地文件夹∙后台文件传输∙使用SD存储卡但不包括：∙本地数据库(基于LINQ的sqlce)∙SQLite本地数据存储概览：打包管理器把所有的App放到"安装文件夹"，App存储数据到"本地文件夹"。

定位存储位置的不同方式：WP8文件存储的备选方案：三种方式// WP7.1 IsolatedStorage APIsvarisf = IsolatedStorageFile.GetUserStoreForApplication();IsolatedStorageFileStreamfs = newIsolatedStorageFileStream("CaptainsLog.store", FileMode.Open, isf)); ...// WP8 Storage APIs using URIStorageFilestorageFile = awaitWindows.Storage.StorageFile.GetFileFromApplicationUriAsync(newUri("ms-appdata:///local/CaptainsLog.store "));...// WP8 Storage APIsWindows.Storage.StorageFolderlocalFolder =Windows.Storage.ApplicationData.Current.LocalFolder;Windows.Storage.StorageFilestorageFile = awaitlocalFolder.GetFileAsync("CaptainsLog.store");用WP7.1的方式：IsolatedStorage类在System.IO.IsolatedStorage命名空间里：∙IsolatedStorage，在独立存储区表达文件和文件夹∙IsolatedFileStream，在IsolatedStorage中暴露一个文件流到文件存储。

∙IsolatedStorageSettings，以键值对（Dictionary<TKey,TValue>）方式存储。

保存数据：privatevoid saveGameToIsolatedStorage(string message){using (IsolatedStorageFileisf =IsolatedStorageFile.GetUserStoreForApplication()){using (IsolatedStorageFileStreamrawStream = isf.CreateFile("MyFile.store")) {StreamWriter writer = new StreamWriter(rawStream);writer.WriteLine(message); // save the messagewriter.Close();}}}读取数据：privatevoid saveGameToIsolatedStorage(string message){using (IsolatedStorageFileisf =IsolatedStorageFile.GetUserStoreForApplication()){using (IsolatedStorageFileStreamrawStream = isf.CreateFile("MyFile.store")) {StreamWriter writer = new StreamWriter(rawStream);writer.WriteLine(message); // save the messagewriter.Close();}}}保存键值对数据：记着在最后调用Save函数保存。

void saveString(string message, string name){IsolatedStorageSettings.ApplicationSettings[name] =message;IsolatedStorageSettings.ApplicationSettings.Save();}读取键值对数据：记着要先检查是否有这个键，否则要抛异常。

string loadString(string name){if (IsolatedStorageSettings.ApplicationSettings.Contains(name)){return (string)IsolatedStorageSettings.ApplicationSettings[name];}elsereturnnull;}WinPRT的存储方式：在Windows.Storage命名空间下：∙StorageFolder∙StorageFile∙不支持ApplicationData.LocalSettings，只能用IsolatedStorageSettings或自定义文件用StorageFolder保存数据：privateasyncvoid saveGameToIsolatedStorage(string message){// Get a reference to the Local FolderWindows.Storage.StorageFolderlocalFolder=Windows.Storage.ApplicationData.Current.LocalFolder;// Create the file in the local folder, or if it already exists, just open itWindows.Storage.StorageFilestorageFile =await localFolder.CreateFileAsync("Myfile.store",CreationCollisionOption.OpenIfExists);Stream writeStream= await storageFile.OpenStreamForWriteAsync();using (StreamWriter writer = new StreamWriter(writeStream)){await writer.WriteAsync(logData);}}读取数据：privateasyncvoid saveGameToIsolatedStorage(string message){// Get a reference to the Local FolderWindows.Storage.StorageFolderlocalFolder=Windows.Storage.ApplicationData.Current.LocalFolder;// Create the file in the local folder, or if it already exists, just open itWindows.Storage.StorageFilestorageFile =await localFolder.CreateFileAsync("Myfile.store",CreationCollisionOption.OpenIfExists);Stream writeStream= await storageFile.OpenStreamForWriteAsync();using (StreamWriter writer = new StreamWriter(writeStream)){await writer.WriteAsync(logData);}}用ms-appdata:/// or ms-appx:/// 保存文件：// There's no FileExists method in WinRT, so have to try to open it and catch exception insteadStorageFilestorageFile = null;bool fileExists = false;try{// Try to open file using URIstorageFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appdata:///local/Myfile.store"));fileExists= true;}catch (FileNotFoundException){fileExists= false;}if (!fileExists){awaitApplicationData.Current.LocalFolder.CreateFileAsync("Myfile.store",Creati onCollisionOption.FailIfExists);}...Windows 8 与Windows Phone 8 兼容性：∙WP8下所有的数据存储用LocalFolder（等效于WP7.1下的IsolatedStorage）∙不支持漫游数据：ApplicationData.Current.RoamingFolder∙临时数据：ApplicationData.Current.RoamingFolder∙本地键值对：ApplicationData.Current.LocalSettings∙漫游键值对：ApplicationData.Current.RoamingSettings∙在Windows8下，可以在用下以代码在XAML元素里加载AppPackages里的图片：RecipeImage.Source = new System.Windows.Media.Imaging.BitmapImage(new Uri(@"ms-appx:///Images/french/French_1_600_C.jpg",UriKind.RelativeOrAbsolute));在Windows Phone8下，不支持这个URI的语法。