private void PlayBtn_Click(object sender, RoutedEventArgs e)
 {
     if (isPaused)
     {
         MusicPlayerMediaElement.Play();
         isPaused = false;
     }
     else
     {
         Play();
     }
 }
        private void PauseBtn_Click(object sender, RoutedEventArgs e)
        {
            if (isPaused)
            {
                MusicPlayerMediaElement.Play();
                isPaused = false;
            }
            else
            {
                MusicPlayerMediaElement.Pause();
                isPaused = true;
            }

            worker.CancelAsync();
        }
 private void Play()
 {
     SetSelectedItemAsMusicPlayerSource();
     MusicPlayerMediaElement.Play();
     isPaused = false;
 }