UWP使用FolderPicker添加仅定义的文件类型

Question

我尝试从文件夹中仅选择所需文件，如下所示：

var folderPicker = new Windows.Storage.Pickers.FolderPicker
        {
            ViewMode = Windows.Storage.Pickers.PickerViewMode.Thumbnail,
            SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.Desktop
        };
        folderPicker.FileTypeFilter.Add(".mp3");
        folderPicker.FileTypeFilter.Add(".mp4");
        folderPicker.FileTypeFilter.Add(".jpeg");
        folderPicker.FileTypeFilter.Add(".jpg");
        folderPicker.FileTypeFilter.Add(".png");

除了".mp3"，".mp4"，".jpeg"，".jpg"和".png"之类的文件之外，不应选择所有其他文件类型。但是不幸的是，代码还添加了所有尚未添加到FileTypeFilter的所有其他文件。

代码中缺少什么？

Answer 1

尝试下面的代码（Microsoft https://docs.microsoft.com/en-us/windows/uwp/files/quickstart-using-file-and-folder-pickers）

 var picker = new Windows.Storage.Pickers.FileOpenPicker();
 picker.ViewMode = Windows.Storage.Pickers.PickerViewMode.Thumbnail;
 picker.SuggestedStartLocation = 
 Windows.Storage.Pickers.PickerLocationId.PicturesLibrary;
 picker.FileTypeFilter.Add(".jpg");
 picker.FileTypeFilter.Add(".jpeg");
 picker.FileTypeFilter.Add(".png");

 Windows.Storage.StorageFile file = await picker.PickSingleFileAsync();