如何使用动画播放媒体

此示例演示如何在同一个Storyboard中同时使用MediaTimeline类和DoubleAnimationUsingKeyFrames类来播放媒体和动画。

示例:

可以将一Storyboard个或多个MediaTimeline对象与其他Timeline对象一起使用,例如动画。

以下示例将 StoryboardSlipBehavior 属性设置为值 Slip,该值规定动画必须等到媒体(此示例中的视频)开始播放后才会进行。 如果媒体播放因加载时间而延迟,则可能需要此功能。

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
  <Canvas>

    <!-- Upper right hand Canvas contains the animations. -->
    <Border BorderBrush="Black" BorderThickness="1"  Canvas.Left="250">
      <Canvas Width="250" Height="250" Background="White" >

        <!-- The two Path elements below create the purple and gold rings
             which are animated while the media is played. -->
        <Path Stroke="Purple" StrokeThickness="5">
          <Path.Data>
            <EllipseGeometry x:Name="MyEllipseGeometry" 
            Center="125,125" RadiusX="15" RadiusY="10" />
          </Path.Data>
        </Path>
        <Path Stroke="Gold" StrokeThickness="5">
          <Path.Data>
            <EllipseGeometry x:Name="MyEllipseGeometry2" 
            Center="125,125" RadiusX="10" RadiusY="15" />
          </Path.Data>
        </Path>
      </Canvas>
    </Border>

    <!-- Upper left hand Canvas contains the video. -->
    <Canvas Width="250" Height="250" Background="Green">
      <MediaElement Name="myvideo" Width="250" Height="250" 
       Canvas.Left="0" Canvas.Top="0">
        <MediaElement.Triggers>
          <EventTrigger RoutedEvent="MediaElement.Loaded">
            <EventTrigger.Actions>
              <BeginStoryboard>

                <!-- This Storyboard contains both media (video in this example) and animations. Note 
               the SlipBehavior value of "Slip" specifies that the animation does not progress
               until the media progresses. This might be desirable if media playback is delayed
               because of loading time. -->
                <Storyboard SlipBehavior="Slip">

                  <!-- The MediaTimeline controls the timing of the video and acts like other Timeline objects.  
                 For example, although the video clip (numbers.wmv) lasts longer, playback ends after six  
                 seconds because that is the duration of the MediaTimeline (Duration="0:0:6"). -->
                  <MediaTimeline Source="media\numbers.wmv" BeginTime="0:0:0" Duration="0:0:10"/>

                  <!-- The animations below animate the ellipses in the right hand pane. These animations are 
                 timed to correspond to the counting in the video. -->

                  <!-- Animate the RadiusY property of the purple ellipse. -->
                  <DoubleAnimationUsingKeyFrames
                    Storyboard.TargetName="MyEllipseGeometry"
                    Storyboard.TargetProperty="RadiusY"
                    RepeatBehavior="10x">
                    <DoubleAnimationUsingKeyFrames.KeyFrames>
                      <LinearDoubleKeyFrame Value="80" KeyTime="0:0:0.4" />
                      <SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="0" KeyTime="0:0:1" />
                    </DoubleAnimationUsingKeyFrames.KeyFrames>
                  </DoubleAnimationUsingKeyFrames>

                  <!-- Animate the RadiusX property of the gold ellipse. -->
                  <DoubleAnimationUsingKeyFrames
                    Storyboard.TargetName="MyEllipseGeometry2"
                    Storyboard.TargetProperty="RadiusX"
                    RepeatBehavior="10x">
                    <DoubleAnimationUsingKeyFrames.KeyFrames>
                      <LinearDoubleKeyFrame Value="80" KeyTime="0:0:0.4" />
                      <SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="0" KeyTime="0:0:1" />
                    </DoubleAnimationUsingKeyFrames.KeyFrames>
                  </DoubleAnimationUsingKeyFrames>

                </Storyboard>
              </BeginStoryboard>
            </EventTrigger.Actions>
          </EventTrigger>
        </MediaElement.Triggers>
      </MediaElement>
    </Canvas>
    
  </Canvas>
</Page>

另请参阅