private async void TestFile()
{
FileOpenPicker fop = new FileOpenPicker();
fop.FileTypeFilter.Add(".flac");
fop.FileTypeFilter.Add(".mp3");
System.Collections.Generic.IReadOnlyList <Windows.Storage.StorageFile> files = await fop.PickMultipleFilesAsync();
foreach (Windows.Storage.StorageFile file in files)
{
HyPlayList.AppendFile(file);
}
HyPlayList.Player.Play();
}