private void PausePlay()
 {
     SongPlayingMediaElement.Pause();
     _audioTimeUpdateTimer.Stop();
     _isPlaying          = false;
     PauseButton.Content = "Ressume";
 }
 private void RessumePlay()
 {
     SongPlayingMediaElement.Play();
     _audioTimeUpdateTimer.Start();
     _isPlaying          = true;
     PauseButton.Content = "Pause";
 }
 private void StopPlay()
 {
     SongPlayingMediaElement.Stop();
     _audioTimeUpdateTimer.Stop();
     UpdateProgressBar();
     _isPlaying = false;
 }
 private void PlayPreviousSong()
 {
     --_index;
     if (_index < 0)
     {
         _index = _selectedSongs.Count - 1;
         SetNextSong();
         return;
     }
     SetNextSong();
     SongPlayingMediaElement.Play();
 }
 private void PlayNextSong()
 {
     ++_index;
     if (_index >= _selectedSongs.Count)
     {
         _index = 0;
         SetNextSong();
         return;
     }
     SetNextSong();
     SongPlayingMediaElement.Play();
 }