Windows 8 Windows 8.1文件OpenPicker

我为windows应用商店制作了应用程序。在我将操作系统升级到Windows8.1之前，它工作得很好。尝试使用FileOpenPicker时出错：

未找到元素。结果：0x80070490

这里是stacktrace：

在Windows.Storage.Pickers.FileOpenPicker.PickSingleFileAsync 在Crypto.Engine.d_u13.MoveNext

和代码：

    FileOpenPicker fop = new FileOpenPicker();
    fop.FileTypeFilter.Add(".jpg");//extension);
    fop.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
    try
    {
        StorageFile file = await fop.PickSingleFileAsync();
        return file;
    }
        catch(Exception ex) {}

---

如何修复它？

我遇到了同样的问题，通过将代码放入正确的线程解决了这个问题：

CoreApplication::MainView->CoreWindow->Dispatcher->RunAsync(
    CoreDispatcherPriority::High,
    ref new DispatchedHandler([]()
{
    // **ATTANTION**: direct call `PickSingleFileAsync` in render loop will crash
    //http://sertacozercan.com/2013/10/fixing-element-not-found-exception-from-hresult-0x80070490-error-in-windows-8-x/
    FileOpenPicker^ openPicker = ref new FileOpenPicker();
    openPicker->ViewMode = PickerViewMode::Thumbnail;
    openPicker->SuggestedStartLocation = PickerLocationId::PicturesLibrary;
    openPicker->FileTypeFilter->Append(".png");
    openPicker->FileTypeFilter->Append(".jpg");
    openPicker->FileTypeFilter->Append(".jpeg");

    auto task = openPicker->PickSingleFileAsync();
}

---

我尝试将我的项目转移到另一台机器上。它有一个错误。我还在Visual Studio 2013中创建了新项目，FileOpenPicker类在这里具有与Visual Studio 2012中不同的属性。2012:[Activatable100794368][MuseVersion=100794368][Version100794368]和2013:[Activatable100794368][MuseVersion=100794368][SupportedOn100794368，Platform.Windows][SupportedOn100794368，Platform.WindowsPhone][Version100794368]。这可能是错误的原因吗？我怎样才能修好它？