private async Task PlaySong()
{
var list = SongList.Where(s => s.GameMark == null);
Random rdm = new Random();
int r = rdm.Next(list.Count());
CurrentSong = list.ElementAt(r);
var file = await StorageFile.GetFileFromPathAsync(CurrentSong.UriStr);
SongPlayer.SetSource(await file.OpenReadAsync(), file.ContentType);
CurrentSong.GameMark = false;
}