Hur du: Anger om en tidslinje automatiskt ska reverseras

En tidslinjes egenskap AutoReverse avgör om den spelas baklänges när den har slutfört en framåtiteration. I följande exempel visas flera animeringar med identisk varaktighet och målvärden, men med olika AutoReverse inställningar. För att visa hur egenskapen AutoReverse beter sig med olika RepeatBehavior inställningar är vissa animeringar inställda på att upprepas. Den senaste animeringen visar hur egenskapen AutoReverse fungerar på kapslade tidslinjer.

Exempel

<!-- AutoReverseExample.xaml
     This example shows how to use the AutoReverse property to make a timeline 
     play backwards at the end of each iteration. 
     Several rectangles are animated by DoubleAnimations with 
     identical durations and target values, but with different
     AutoReverse and RepeatBehavior settings.-->
     
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  WindowTitle="AutoReverse Example">
  <StackPanel Margin="20">

    <!-- Create some rectangles to animate. -->
    <Rectangle Name="withoutAutoReverseRectangle"
      Width="100" Height="20" Fill="Blue" />  

    <Rectangle Name="autoReverseRectangle"
      Width="100" Height="20" Fill="Blue" />

    <Rectangle Name="autoReverseRectangleWithRepeats"
      Width="100" Height="20" Fill="Blue" />

    <Rectangle Name="complexAutoReverseExample"
      Width="100" Height="20" Fill="Blue"  />

    <!-- Use a button to restart the animations. -->
    <Button Margin="30" Content="Start Animations">
      <Button.Triggers>
        <EventTrigger RoutedEvent="Button.Click">
          <BeginStoryboard>
            <Storyboard>

              <!-- Create an animation that does not automatically play in reverse.
                   This animation plays for a total of 2 seconds. -->
              <DoubleAnimation 
                Storyboard.TargetName="withoutAutoReverseRectangle" 
                Storyboard.TargetProperty="Width" 
                Duration="0:0:2" From="100" To="400" AutoReverse="False" />   

              <!-- Create an animation that automatically reverses at the end of each iteration.
                   This animation plays for a total of 4 seconds. -->
              <DoubleAnimation Storyboard.TargetName="autoReverseRectangle" 
                Storyboard.TargetProperty="Width"
                Duration="0:0:2" From="100" To="400" AutoReverse="True" />
        
              <!-- Create an animation that automatically reverses at the end of each iteration.
                   Set the animation to repeat twice. As a result, then animation plays forward,
                   the backward, then forward, and then backward again. 
                   This animation plays for a total of 8 seconds. -->
              <DoubleAnimation Storyboard.TargetName="autoReverseRectangleWithRepeats" 
                Storyboard.TargetProperty="Width"
                Duration="0:0:2" From="100" To="400" AutoReverse="True" RepeatBehavior="2x" />  
                
              <!-- Set the parent timeline's AutoReverse property to True and set the animation's
                   RepeatBehavior to 2x. As a result, the animation plays forward twice and then
                   backwards twice. 
                   This animation plays for a total of 8 seconds. -->                
              <ParallelTimeline AutoReverse="True">
                <DoubleAnimation 
                  Storyboard.TargetName="complexAutoReverseExample" 
                  Storyboard.TargetProperty="Width"
                  Duration="0:0:2" From="100" To="400" RepeatBehavior="2x"  />  
              </ParallelTimeline>
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Button.Triggers>
    </Button>
  </StackPanel>
</Page>