private void SelectPlaylist(object sender, RoutedEventArgs e)
        {
            ViewModelPlaylist context = this.DataContext as ViewModelPlaylist;

            playlist     = this.ListPlaylist.SelectedValue as Playlist;
            bHasReturned = true;
            this.Close();
        }
 void loader_worker_DoWork(object sender, DoWorkEventArgs e)
 {
     ToggleProgressBar("Loading...");
     vmp = new ViewModelPlaylist();
     while (!vmp.Completed)
     {
         System.Threading.Thread.Sleep(3000);
     }
 }