c# - Windows 8 - WriteTextAsync 异常 "Cannot evaluate expression because a native frame is on top of the call stack."

Question

我想使用 StorageFile 来实现读取和写入，如下所示

http://msdn.microsoft.com/en-us/library/windows/apps/hh758325.aspx#writing_to_a_file

与

public async void Save()
{
    StorageFolder storageFolder = KnownFolders.DocumentsLibrary;
    StorageFile sampleFile = await storageFolder.CreateFileAsync(PlayerPrefs.GetString("WorldName") +"_"+filename);
    await Windows.Storage.FileIO.WriteTextAsync(sampleFile, "Swift as a shadow");
}

但是“await”行给出了异常

+    $exception {Cannot evaluate expression because a native frame is on top of the call stack.} System.Exception {System.UnauthorizedAccessException}

如果这有任何不同，我将 Unity 与 Windows 8 应用商店一起使用。

有人知道这里的问题是什么吗？

Answer 1

Cannot evaluate expression because a native frame is on top of the call stack

这只告诉我们线程正在执行 unmanaged code ，因此它无法计算表达式。

真正的错误是 System.UnauthorizedAccessException。

因此，打开您的Package.appxmanifest，转到Capabilities 选项卡并选中Document Library Access。