C# 使用WPF 用MediaElement控件实现视频循环播放

XAML：
    <MediaElement x:Name="mediaElement" HorizontalAlignment="Left" Height="261" VerticalAlignment="Top" Width="507"/>
    <Button x:Name="btnPlay" Content="Play" HorizontalAlignment="Left" Margin="68,279,0,0" VerticalAlignment="Top" Width="75" Click="btnPlay_Click"/>
    <Button x:Name="btnPause" Content="Pause" HorizontalAlignment="Left" Margin="170,279,0,0" VerticalAlignment="Top" Width="75" Click="btnPause_Click"/>
    <Button x:Name="btnStop" Content="Stop" HorizontalAlignment="Left" Margin="295,279,0,0" VerticalAlignment="Top" Width="75" Click="btnStop_Click"/>

C#：
    // 窗口加载事件
    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
      // 绑定视频文件
      mediaElement.Source = new Uri("D:/bird.mp4");
      // 交互式控制
      mediaElement.LoadedBehavior = MediaState.Manual;
      // 添加元素加载完成事件 -- 自动开始播放
      mediaElement.Loaded += new RoutedEventHandler(media_Loaded); 
      // 添加媒体播放结束事件 -- 重新播放
      mediaElement.MediaEnded += new RoutedEventHandler(media_MediaEnded);
      // 添加元素卸载完成事件 -- 停止播放
      mediaElement.Unloaded += new RoutedEventHandler(media_Unloaded);
    }
    /*
      元素事件 
    */
    private void media_Loaded(object sender, RoutedEventArgs e)
    {
      (sender as MediaElement).Play();
    }
    private void media_MediaEnded(object sender, RoutedEventArgs e)
    {
      // MediaElement需要先停止播放才能再开始播放，
      // 否则会停在最后一帧不动
      (sender as MediaElement).Stop();
      (sender as MediaElement).Play();
    }
    private void media_Unloaded(object sender, RoutedEventArgs e)
    {
      (sender as MediaElement).Stop();
    }
    /*
      播放控制按钮的点击事件 
    */
    private void btnPlay_Click(object sender, RoutedEventArgs e)
    {
      mediaElement.Play();
    }
    private void btnPause_Click(object sender, RoutedEventArgs e)
    {
      mediaElement.Pause();
    }
    private void btnStop_Click(object sender, RoutedEventArgs e)
    {
      mediaElement.Stop();
    }

XAML:
    <MediaElement x:Name="mediaElement" HorizontalAlignment="Left" Height="243" Margin="19,10,0,0" VerticalAlignment="Top" Width="394" LoadedBehavior ="Manual"/>
    <Button x:Name="btnPlay" Content="Play" HorizontalAlignment="Left" Margin="52,270,0,0" VerticalAlignment="Top" Width="75" Click="btnPlay_Click"/>
    <Button x:Name="btnPause" Content="Pause" HorizontalAlignment="Left" Margin="163,270,0,0" VerticalAlignment="Top" Width="75" Click="btnPause_Click"/>
    <Button x:Name="btnStop" Content="Stop" HorizontalAlignment="Left" Margin="266,270,0,0" VerticalAlignment="Top" Width="75" Click="btnStop_Click"/>

C#：
    DispatcherTimer timer = new DispatcherTimer(); // 定时器timer
    int durTime = 5; // 视频播放时长，也就是循环周期
    // 窗口加载事件
    private void Window_Loaded(object sender, RoutedEventArgs e) 
    {
      mediaElement.Source = new Uri("D:/bird.mp4"); // 绑定视频文件
      mediaElement.Play(); // 设置启动播放
      timer.Interval = new TimeSpan(0, 0, 0, durTime); // 设置定时器重复周期
      timer.Tick += new EventHandler(timerEvent); // 设置定时器事件
      timer.Start(); // 启动定时器
    }
    // 定时器事件 
    public void timerEvent(object sender, EventArgs e)
    {
      // MediaElement需要先停止播放才能再开始播放，
      // 否则会停在最后一帧不动
      mediaElement.Stop(); 
      mediaElement.Play(); 
    }
    /*
      播放控制按钮的点击事件 
    */
    private void btnPlay_Click(object sender, RoutedEventArgs e)
    {
      mediaElement.Play(); // 开始播放
      timer.Start(); // 重新启动定时器
    }
    private void btnPause_Click(object sender, RoutedEventArgs e)
    {
      mediaElement.Pause(); // 暂停当前播放
      timer.Stop(); // 停止定时器
    }
    private void btnStop_Click(object sender, RoutedEventArgs e)
    {
      mediaElement.Stop(); // 停止当前播放
      timer.Stop(); // 停止定时器
    }