MediaElement和thread.sleep的问题

Question

我正在从组合框中进行选择更改。当该事件发生时，我想播放一个媒体文件，暂停5秒然后播放另一个媒体文件。实际发生的是暂停5秒。然后只播放第二个媒体文件（vb.mp4）。我在这里做错了什么？

private void cmb_adGroupZoneOne_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
       this.mediaElement.Source = new Uri("C:/fb.mp4");
       this.mediaElement.LoadedBehavior = MediaState.Manual;
       this.mediaElement.Play();

       System.Threading.Thread.Sleep(5000);

       this.mediaElement.Source = new Uri("C:/vb.mp4");
       this.mediaElement.LoadedBehavior = MediaState.Manual;
       this.mediaElement.Play();
    }

Answer 1

<MediaElement Name="mediaElement" MediaEnded="mediaElement_MediaEnded"  />

private void cmb_adGroupZoneOne_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
       this.mediaElement.Source = new Uri("C:/fb.mp4");
       this.mediaElement.LoadedBehavior = MediaState.Manual;
       this.mediaElement.Play();

    }


private void mediaElement_MediaEnded(object sender, RoutedEventArgs e)
{

       System.Threading.Thread.Sleep(5000);

       this.mediaElement.Source = new Uri("C:/vb.mp4");
       this.mediaElement.LoadedBehavior = MediaState.Manual;
       this.mediaElement.Play();  
}