如何：使用关键帧对字符串进行动画处理
此示例演示如何使用关键帧对字符串（本例中为 Button 控件的 Content 属性）进行动画处理。
示例
下面的示例使用 StringAnimationUsingKeyFrames 类对 Button 的 Content 属性进行动画处理。
此示例中的所有关键帧均使用 DiscreteStringKeyFrame 类的实例，因为用关键帧创建的字符串动画只能使用离散关键帧。 离散关键帧（如 DiscreteStringKeyFrame）将使值发生突变，也就是说，动画变化是快速发生的，并且不是细微变化。
<!-- Demonstrates the StringAnimationUsingKeyFrames class. A StringAnimationUsingKeyFrames is used to
animate the TextContent property of a Text element. -->
<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://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>
有关完整示例，请参见 KeyFrame Animation Sample（KeyFrame 动画示例）。