如何在WPF中向后播放视频？(How to play video backwards in WPF?)

 我希望在WPF中顺利播放视频。 我正在使用MediaElement播放视频。 我读过这篇文章建议定期更改MediaElement.Position以模仿倒带行为。 
 
 我尝试使用代码来更改MediaElement.Position位置 
 
private void Button_Click(object sender, RoutedEventArgs e)
{
    mePlayer.Pause();                               //Pause the media player first
    double m = 1 / frameRate;                       //Calculate the time for each frame
    double t = 120;                                 //Total length of video in seconds
    mePlayer.Position = TimeSpan.FromMinutes(2);    //Start video from 2 min
    while (t >= 60)                                 //Check if time exceeds 1 min
    {
        t = t - m;                                  //Subtract the single frame time from total seconds
        mePlayer.Position = TimeSpan.FromSeconds(t);//set position of video
    }
}
 
 在上面的代码中，我试图从2分钟到1分钟向后播放视频。 它在mePlayer.Position = TimeSpan.FromSeconds(t)上给我'System.OverflowException'。 
 
 如果有人知道如何在WPF中向后播放视频，请帮助我实现此效果。 谢谢。 

I want to smoothly play video in backwards direction in WPF. I am using MediaElement to play the video. I read this post which suggests changing MediaElement.Position periodically to mimic the rewinding behaviour.
 
I tried following code for changing position of MediaElement.Position
 
private void Button_Click(object sender, RoutedEventArgs e)
{
    mePlayer.Pause();                               //Pause the media player first
    double m = 1 / frameRate;                       //Calculate the time for each frame
    double t = 120;                                 //Total length of video in seconds
    mePlayer.Position = TimeSpan.FromMinutes(2);    //Start video from 2 min
    while (t >= 60)                                 //Check if time exceeds 1 min
    {
        t = t - m;                                  //Subtract the single frame time from total seconds
        mePlayer.Position = TimeSpan.FromSeconds(t);//set position of video
    }
}
 
In above code I am trying to play video backwards from 2 min to 1 min. It's giving me 'System.OverflowException' on mePlayer.Position = TimeSpan.FromSeconds(t).
 
If anyone know how play video backwards in WPF, please help me to achieve this effect. Thank you.

原文：https://stackoverflow.com/questions/30955604