c# - 调用 FileOpenPicker.PickSingleFileAndContinue() 时总是得到 "Access is denied"

Question

我在为我的 WP 8.1 应用程序编码时调用 FileOpenPicker.PickSingleFileAndContinue 时卡住了。我所做的只是在我的类中的 OnLoaded 方法中运行以下代码，该类继承自 Page 类。

FileOpenPicker openPicker = new FileOpenPicker();
openPicker.ViewMode = PickerViewMode.List;
openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
openPicker.FileTypeFilter.Add(".pdf");
openPicker.FileTypeFilter.Add(".PDF");
openPicker.PickSingleFileAndContinue();

并且在调用 PickSingleFileAndContinue() 方法后，总是抛出带有以下消息的异常:

"System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))\r\n at Windows.Storage.Pickers.FileOpenPicker.PickSingleFileAndContinue()

我可能在代码上做错了，但是在哪里。任何人都得到了我的帮助。谢谢。

Answer 1

来自 MSDN 的回答:

Your FileOpenPicker code is fine. 
The problem is that you can't call it from your page load.
If you delay it a bit or (better) call it in response to user
action then your code snippet will work.

这就解决了问题。