private void RewindAction() { _player.Rewind(10000); _seconds -= 10000; PlayingProgress -= 10000; if (_seconds < 0) { _seconds = 0; } if (PlayingProgress < 0) { PlayingProgress = 0; } string displayProgress = TimeSpan.FromMilliseconds(_seconds).ToString("mm\\:ss"); ElapsedTime = displayProgress + " / " + PlayingSong.DisplayDuration; }