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How to: Animate a String by Using Key Frames

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This example shows how to animate a string, which in this example is the Content property of a Button control, by using key frames.

Example

The following example uses the StringAnimationUsingKeyFrames class to animate the Content property of a Button.

All the key frames in this example use an instance of the DiscreteStringKeyFrame class because a string animation that is created with key frames can only use discrete key frames. Discrete key frames like DiscreteStringKeyFrame create sudden jumps between values, that is, changes to the animation occur quickly and are not subtle.

<!-- Demonstrates the StringAnimationUsingKeyFrames class. A StringAnimationUsingKeyFrames is used to
   animate the TextContent property of a Text element. -->
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  x:Class="Microsoft.Samples.KeyFrameExamples.StringAnimationUsingKeyFramesExample"
  Name="myRootElement"
  WindowTitle="StringAnimationUsingKeyFrames Example">

  <StackPanel HorizontalAlignment="Center">
    <Button Name="myAnimatedButton" Margin="200"
      FontSize="16pt" FontFamily="Verdana">Some Text
      <Button.Triggers>
        <EventTrigger RoutedEvent="Button.Click">
          <BeginStoryboard>
            <Storyboard>
              <StringAnimationUsingKeyFrames 
                Storyboard.TargetName="myAnimatedButton" Storyboard.TargetProperty="(Button.Content)"
                Duration="0:0:8" FillBehavior="HoldEnd">

                <!-- All the key frames below are DiscreteStringKeyFrames. Discrete key frames create 
                sudden "jumps" between values (no interpolation). Only discrete key frames can be used 
                for String key frame animations. -->
                <DiscreteStringKeyFrame Value="" KeyTime="0:0:0" />
                <DiscreteStringKeyFrame Value="A" KeyTime="0:0:1" />
                <DiscreteStringKeyFrame Value="An" KeyTime="0:0:1.5" />
                <DiscreteStringKeyFrame Value="Ani" KeyTime="0:0:2" />
                <DiscreteStringKeyFrame Value="Anim" KeyTime="0:0:2.5" />
                <DiscreteStringKeyFrame Value="Anima" KeyTime="0:0:3" />
                <DiscreteStringKeyFrame Value="Animat" KeyTime="0:0:3.5" />
                <DiscreteStringKeyFrame Value="Animate" KeyTime="0:0:4" />
                <DiscreteStringKeyFrame Value="Animated" KeyTime="0:0:4.5" />
                <DiscreteStringKeyFrame Value="Animated " KeyTime="0:0:5" />
                <DiscreteStringKeyFrame Value="Animated T" KeyTime="0:0:5.5" />
                <DiscreteStringKeyFrame Value="Animated Te" KeyTime="0:0:6" />
                <DiscreteStringKeyFrame Value="Animated Tex" KeyTime="0:0:6.5" />
                <DiscreteStringKeyFrame Value="Animated Text" KeyTime="0:0:7" />
              </StringAnimationUsingKeyFrames>              
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger> 
      </Button.Triggers>
    </Button>
  </StackPanel>
</Page>

For the complete sample, see KeyFrame Animation Sample.

See also