title: Combining MediaTimeline with animation in Storyboard programmatically
body: <p>I am trying to use MediaTimeline and DoubleAnimation inside Storyboard to play audio with animation. Everything is implemented in C# without XAML. Nothing happens after Storyboard.Begin is called in the code below and no exception is thrown. mediaElement's HasAudio property is false and MediaOpened event of MediaElement is never called. It seems mediaElement can't load the audio file. I don't know whether MediaElement or MediaTimeline is responsible for loading the audio. DoubleAnimation works fine without the MediaTimeline. What am I missing here?</p>
  
  <pre><code>private void SetStoryboard(double beginLeft, double endLeft, TimeSpan duration)
  {
          mediaElement = new MediaElement();
          mediaElement.LoadedBehavior = MediaState.Manual;
          mediaElement.ScrubbingEnabled = true;
          mediaElement.MediaOpened += new RoutedEventHandler(MediaElement_MediaOpened);
  
          mediaTimeline = new MediaTimeline();
          mediaTimeline.Duration = new Duration(duration);
          mediaTimeline.Source = new Uri(musicFilePath);
          mediaTimeline.FillBehavior = FillBehavior.Stop;
          Storyboard.SetTarget(mediaTimeline, mediaElement);
  
          anim = new DoubleAnimation();
          anim.From = beginLeft;
          anim.To = endLeft;
          anim.Duration = new Duration(duration);
          anim.FillBehavior = FillBehavior.Stop;
          Storyboard.SetTarget(anim, slider);
          Storyboard.SetTargetProperty(anim, new PropertyPath(Canvas.LeftProperty));
  
          storyboard = new Storyboard();
          storyboard.SlipBehavior = SlipBehavior.Slip;
          storyboard.Children.Add(mediaTimeline);
          storyboard.Children.Add(anim);
  
          storyboard.Begin(this, true);
  }
  </code></pre>