c# - Windows Phone 8.1 文件打开选择器页面导航错误

Question

private void Gallery_Click(object sender, object e)
{
    view = CoreApplication.GetCurrentView();
    var filePicker = new FileOpenPicker
    {
        SuggestedStartLocation = PickerLocationId.PicturesLibrary,
        ViewMode = PickerViewMode.Thumbnail
    };

    // Filter to include a sample subset of file types
    filePicker.FileTypeFilter.Clear();
    filePicker.FileTypeFilter.Add(".bmp");
    filePicker.FileTypeFilter.Add(".png");
    filePicker.FileTypeFilter.Add(".jpeg");
    filePicker.FileTypeFilter.Add(".jpg");

    mediaCapture.StopPreviewAsync();

    filePicker.PickSingleFileAndContinue();
    view.Activated += ViewActivated;
}

private async void ViewActivated(CoreApplicationView sender, IActivatedEventArgs args)
{
    var arguments = args as FileOpenPickerContinuationEventArgs;

    if (arguments != null && arguments.Files.Count != 0)
    {
        view.Activated -= ViewActivated;
        var storageFile = arguments.Files[0];

        var file =
            await
                ApplicationData.Current.LocalFolder.CreateFileAsync("Photo.jpg",
                    CreationCollisionOption.GenerateUniqueName);
        await storageFile.CopyAndReplaceAsync(file);

        var bmpImage = new BitmapImage(new Uri(file.Path));

        UseThePhoto(bmpImage);                
    }
    else
        await mediaCapture.StartPreviewAsync();

}

我上面有这段代码。当我从图库中选择图像时，我可以在同一页面上的图像控件中使用它。但是，如果我想导航到任何其他页面，我会收到错误消息。没有任何细节。代码以 App.gics 结尾

Answer 1

问题解决了。我使用的不是空白页面模板，而是基本页面。由于某种原因，方法 OnNavigatedFrom 调用了这个错误，所以我创建了一个覆盖并让它为空，所以它不能调用导航助手类。