通过

如何：使用 From、To 和 By 控制动画

  • 项目

“From/To/By”或“basic animation”在两个目标值之间创建转换（请参阅 动画概述 ，了解不同类型的动画简介）。 若要设置基本动画的目标值，请使用其FromTo和By属性。 下表总结了如何将From和ToBy属性一起使用或单独用于确定动画的目标值。

指定的属性 产生的行为
From 动画从属性指定的 From 值发展到要进行动画处理的属性的基值或上一动画的输出值，具体取决于上一个动画的配置方式。
From 和 To 动画从属性指定的 From 值发展到属性指定的 To 值。
From 和 By 动画从From属性指定的值发展到由From属性和By属性之和指定的值。
To 动画从动画属性的基值或上一动画的输出值发展到属性指定的 To 值。
By 动画的进展从属性的基值或之前动画的输出值开始，到达到该值与By属性指定的值之和。

注释

不要在同一动画上同时设置To 属性和By 属性。

若要使用其他内插方法或在两个以上目标值之间进行动画处理，请使用关键帧动画。 有关详细信息 ，请参阅Key-Frame 动画概述 。

有关将多个动画应用于单个属性的信息，请参阅 Key-Frame 动画概述。

下面的示例显示了设置To、By和From属性对动画效果的不同影响。

示例：

<!-- This example shows the different effects of setting
   To, By, and From properties on animations.  -->
<Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

  <StackPanel Margin="20">

    <!-- Demonstrates the From and To properties used together. -->
    <Rectangle Name="fromToAnimatedRectangle" Height="10" Width="100" 
      HorizontalAlignment="Left" Margin="10" Fill="#99FF9900" />

    <!-- Demonstrates the use of the To property. -->
    <Rectangle Name="toAnimatedRectangle" Height="10" Width="100" 
      HorizontalAlignment="Left" Margin="10" Fill="#99FF9900" />

    <!-- Demonstrates the use of the By property. -->
    <Rectangle Name="byAnimatedRectangle" Height="10" Width="100" 
      HorizontalAlignment="Left" Margin="10" Fill="#99FF9900" />

    <!-- Demonstrates the use of the From and By properties. -->
    <Rectangle Name="fromByAnimatedRectangle" Height="10" Width="100" 
      HorizontalAlignment="Left" Margin="10" Fill="#99FF9900" />

    <!-- Demonstrates the use of the From property. -->
    <Rectangle Name="fromAnimatedRectangle" Height="10" Width="100" 
      HorizontalAlignment="Left" Margin="10" Fill="#99FF9900" />
    <Button>
      Start Animations
      <Button.Triggers>
        <EventTrigger RoutedEvent="Button.Click">
          <BeginStoryboard>
            <Storyboard FillBehavior="Stop">

              <!-- Demonstrates the From and To properties used together.
                 Animates the rectangle's Width property from 50 to 300 over 10 seconds. -->
              <DoubleAnimation 
                Storyboard.TargetName="fromToAnimatedRectangle" 
                Storyboard.TargetProperty="(Rectangle.Width)"
                From="50" To="300" Duration="0:0:10" />

              <!-- Demonstrates the To property used by itself.
                 Animates the Rectangle's Width property from its base value
                 (100) to 300 over 10 seconds. -->
              <DoubleAnimation 
                Storyboard.TargetName="toAnimatedRectangle" Storyboard.TargetProperty="(Rectangle.Width)"
                To="300" Duration="0:0:10" />

              <!-- Demonstrates the By property used by itself.
                 Increments the Rectangle's Width property by 300 over 10 seconds.
                 As a result, the Width property is animated from its base value
                 (100) to 400 (100 + 300) over 10 seconds. -->
              <DoubleAnimation 
                Storyboard.TargetName="byAnimatedRectangle" Storyboard.TargetProperty="(Rectangle.Width)" 
                By="300" Duration="0:0:10" />

              <!-- Demonstrates the From and By properties used together.
                 Increments the Rectangle's Width property by 300 over 10 seconds.
                 As a result, the Width property is animated from 50
                 to 350 (50 + 300) over 10 seconds. -->
              <DoubleAnimation 
                Storyboard.TargetName="fromByAnimatedRectangle" Storyboard.TargetProperty="(Rectangle.Width)" 
                From="50" By="300" Duration="0:0:10"  />

              <!-- Demonstrates the From property used by itself.
                 Animates the rectangle's Width property from 50 to its base value (100)
                 over 10 seconds. -->
              <DoubleAnimation 
                Storyboard.TargetName="fromAnimatedRectangle" Storyboard.TargetProperty="(Rectangle.Width)"
                From="50" Duration="0:0:10"  />
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Button.Triggers>
    </Button>
  </StackPanel>
</Page>

另请参阅