如何關閉打開的StorageFile？

我正在編寫一個Windows Phone 8.1（WINRT XAML）應用程序。如何關閉打開的StorageFile？

在方法1中，我打開一個StorageFile，並在方法2中寫入同一個文件中的。但是在寫入文件時顯示錯誤。

如何打開和閱讀內容後關閉此文件？

那麼如何在寫入方法2之後再次關閉此文件？

private async Task<bool> Method1(int workOutID) { string filename = "WorkoutOfflineDataFile.txt"; StorageFolder LocalStorageFolderObject = ApplicationData.Current.LocalFolder; StorageFile StorageFileObject = await LocalStorageFolderObject.CreateFileAsync(filename, CreationCollisionOption.OpenIfExists); string JSONFromFile = await FileIO.ReadTextAsync(StorageFileObject); } private async void Method2() { string filename = "WorkoutOfflineDataFile.txt"; StorageFolder LocalStorageFolderObject = ApplicationData.Current.LocalFolder; StorageFile StorageFileObject = await LocalStorageFolderObject.CreateFileAsync(filename, CreationCollisionOption.OpenIfExists); await FileIO.WriteTextAsync(StorageFileObject, JSonData_ToSave); }

ERROR:

Exception thrown: 'System.UnauthorizedAccessException' in mscorlib.ni.dll

Additional information: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

來源

2015-10-05 Atif Shabeer

請將您的代碼粘貼到代碼塊中。現在它不可讀。 – Festyk

@Festyk，請立即檢查 –

您打算如何調用這些方法？ –

不Festyk的解決方案的工作？也許只是試着用：

StorageFile StorageFileObject = await LocalStorageFolderObject.GetFileAsync(filename);

在你的第二種方法中，如果你確定文件已經存在 - 記住，否則它會拋出一個異常。

來源

2015-10-05 18:05:28 marcinax

WorkoutOfflineDataFile.txt在第一個方法中打開。我不知道如何關閉它的處理程序。它不在method2中打開。顯示，UnauthorizedAccessException –

代碼似乎是正確的，我認爲異常是由其他東西引發的。

無論如何，如果你想，以確保您的文件和數據流的讀/寫操作後關閉，您可以用一次性方式：

private async Task<bool> Method1(int workOutID) 
{ 
    string filename = "WorkoutOfflineDataFile.txt"; 
    StorageFolder LocalStorageFolderObject = ApplicationData.Current.LocalFolder; 
    StorageFile StorageFileObject = await LocalStorageFolderObject.CreateFileAsync(filename, CreationCollisionOption.OpenIfExists); 
    using (var stream = await StorageFileObject.OpenStreamForReadAsync()) 
    { 
     using (var reader = new StreamReader(stream)) 
     { 
      string JSONFromFile = reader.ReadToEnd(); 
     } 
    } 
} 

private async void Method2() 
{ 
    string filename = "WorkoutOfflineDataFile.txt"; 
    StorageFolder LocalStorageFolderObject = ApplicationData.Current.LocalFolder; 
    StorageFile StorageFileObject = await LocalStorageFolderObject.CreateFileAsync(filename, CreationCollisionOption.OpenIfExists); 
    using (var stream = await StorageFileObject.OpenStreamForWriteAsync()) 
    { 
     using (var writer = new StreamWriter(stream)) 
     { 
      writer.Write(JSonData_ToSave); 
     } 
    } 
}

來源

2015-10-07 07:26:37

你鎖定在方法1文件（）

private async Task<bool> Method1(int workOutID) 
{ 
    string filename = "WorkoutOfflineDataFile.txt"; 
    StorageFolder LocalStorageFolderObject = ApplicationData.Current.LocalFolder; 
    StorageFile StorageFileObject = await LocalStorageFolderObject.CreateFileAsync(filename, CreationCollisionOption.OpenIfExists); 
    string JSONFromFile = await FileIO.ReadTextAsync(StorageFileObject); 
}

當你試圖訪問WorkoutOfflineDataFile.txt你實際上鎖定這個文件，所以沒有其他線程可以觸摸它，直到它關閉。

盧卡的答案似乎很好，也很安全。嘗試使用它。

來源

2015-10-07 17:00:36

如何關閉打開的StorageFile？

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