Windows Phone 8文件和存儲
WP7.1 IsolatedStorage和IsolatedStorageSetting是 APIs
“本地存儲”和“獨立存儲”
讀取文件的不同方式：
Local Database data context
Files acess using WP7.1 Isolated Storage API
Files access using Windows.Storage API via URIs
File access using Windows.Storage API via StorageFolder references
WP8文件訪問的選擇：
//WP7.1 IsolatedStorage APIs
Var isf=IsolatedStorageFile.GetUserStoreForApplication();
IsolatedStorageFileStream fs=newIsolatedStorageFileStream("CaptainsLog.store",FileMode.Open,isf));
···
//WP8 Storage APIs using URI
StorageFile StorageFile=awaitWindowsd.Storage.StorageFile.GetFileFromApplicationUriAsync(newUri("ms-appdata:///local/CaptainsLog.store"));
```
//WP8 Storage APIs
Windows.Storage.StorageFolderlocalFolder=Windows.Storage.ApplicationData.Current.LocalFolder;
Windows.Storage.StorageFile storageFile=awaitlocalFolder.GetFileAsync("CaptainsLog.store");
```
使用WP7.1獨立存儲API保存數據
Isolated Storage Classes
IsolatedStorageFile
IsolatedFileStream
IsolatedStorageSettings
Saving Data
Private void saveGameToIsolatedStorage(string message)
{
Using(isolatedStorageFileisf=IsolatedStorageFile.GetUserStoreForApplication())
{
Using(IsolatedStorageFileSytreamrawStream=isf.CreaqteFile("MyFile.store"))
{
StreamWriter writer=new StreamWriter(rawStream);
Writer.WriteLine(message); //save the message
Writer.Close();
}
}
Loading Data
Private String loadString()
{
String result=null;
Using(IsolatedStorageFileisf=IsolostedStorageFile.GetUserStoreForApplication())
{
If(isf.FileExists("Myfile.store")
{
Using(IsolatedStorageFileStreamrawStream=isf.OpenFile(filename,System.IO.FileMode.Open())
{
StreamReader reader=newStreamReader(rawStream);
Result=reader.ReadLine();
Reader.Close();
}
}
}
Return result;
}
在應用設備中保存數據
Void saveString(streing message,string name)
{
IsolatedStorageSettings.ApplicationSettings[name]=message;
IsolatedStorageSettings.ApplicationSettings.Save();
使用設置存儲
使用StorageFolder保存數據
Using System.IO;
Using Windows.Storage;
```
Private async void saveToLocalFolderAsync(string message)
{
//Get a reference to the Local Folder
StorageFolder localFolder=ApplicationData.Current.LocalFolder;
//Create the file in the local folder, or if it already exists, justopen it
StorageFile storageFile=await storageFile.OpenStreamForWreteAsync();
Using(StreamWriter writer=new StreamWriter(writeStream))
{
Await writer.WriteAsync(logData);
}
}
使用ms-appdata:///local/or ms-appx:///訪問文件
//There's no FileExists method in WinRT, so have to try to open itand catch exception instead
StorageFile storageFile=null;
Bool fileExists=false;
Try
{
//Try to open file using URI
storageFile=await StorageFile.GetFileFromApplicationUriAsync(
NewUri("ms-appdata:///local/Myfile,store")；
fileExists=true;
}
Catch(FileNotFoundException)
{
fileExists=false;
}
If(!fileExists)
{
AwaitApplicationData.Current.LoaclFolder.CreateFileAsync("Myfile.store",CreationCollisionOption.FaqilIfExists);
}
```
Windows.comStorage（WindowsPhoneRunting）編程
Windows Phone8和Windows8兼容性
在Windows8中您可以以編程的方式加載應用程序包中的圖像文件，將圖像加載至XAML<Image>元素，代碼如下：
RecipeImage.Source=new System.Windows.Media.Imaging.BitmapImage(newUri(@"ms-appx:///Images/french/French_1_600_C.jpg",UriKind.RelativeOrAbsolute));
在WindowsPhone8中不能使用這樣的URI語法，只能使用WindowsPhone OS7.1中的相對路徑，代碼如下：
RecipeImage.Source=newSystem.Windows.Media.Imgine.BitmapImage("/Images/french/French_1_600_C.jpg");
特殊文件夾
Shared/Media專輯封面
Shared/ShellContent圖塊
Shared/Transfers後臺文件傳輸
數據的序列化和反序列化(將對象集合的屬性寫入文件以便永久保存）
->Deactivated/Closig->Not running->Launching->Running
使用DataContractSerializer實現序列化
Public class MyDataSerializer<TheDataType>
{
Public static async Task SaveObjectsAsync(TheDataTypesourceData,String targetFileName)
{
StorageFile file=await|ApplicationData.Current.LocalFolder.CreateFileAsync(
targertFileName,CreationCollisionOpetion.ReplaceExisting);
Var outStream=await file.OpenStreamForWriteAsync();
DataContractSerializer serializer=newDataContractSerizlizer(typeof(TheDataType));
Serializer.WriteObject(outStream,sourceData);
Await outStream.FlushAsync();
outStream.Close();
}
```
}
使用DataContractSerializer實現反序列化
Puboic class MyDataSerializer<TheDataType>
{
Public static async Task<TheDataType>RestoreObjectsAsync(string fileName)
{
StorageFile file=awaitApplicationData.Current.LocalFolder.GetFileAsync(fileName);
Var inStream=await file.OpenstreamForReadAsync();
//Deserialize the objects.
DataContractSerializer serializer=newDataContractSerializer(typeof(TheDataType));
TheDataType data=(TheDataType)serializer.ReadObject(inStream);
inStream.Close();
Return data;
}
````
}
使用獨立存儲資源管理器ISETool.exe
語法：
Ts-Take snapshot
Re-Restore snapshot
Dir-lists the files or dirextories
使用可移動的SD卡
外部存儲（SD）卡（Windows Phone8 支持使用SD卡）
<Extensions>
<FileTypeAssociation Name="foo"TaskID="_default" NavUriFragment="fileToken=%s">
<SupportedFileTypes>
<FileTypeContentType="application/foo">.foo</FileType>
</SupportedFileTypes>
</FileTypeAssociation>
</Extensions>
在WMAppMainifest.xml中聲明文件關聯
<Extensions>
<FileTypeAssociation Name="foo"TaskID="_default" NavUriFragment="fileToken=%s">
<SupportedFileTypes>
<FileTypeContentType="application/foo">.foo</FileType>
</SupportedFileTypes>
</FileTypeAssociation>
</Extensions>
最佳方法：
配額管理
Serialization and Threads
