通过

如何：使用 From、To 和 By 控制动画

  • 项目

“From/To/By”或“基本动画”在两个目标值之间创建转换（有关不同类型的动画简介，请参阅动画概述）。 若要设置基本动画的目标值，请使用其 From、To 和 By 属性。 下表总结了如何结合使用或单独使用 From、To 和 By 属性来确定动画的目标值。

指定的属性 产生的行为
From 该动画从 From 属性指定的值前进到要进行动画处理的属性的基值或前一个动画的输出值，具体取决于前一个动画的配置方式。
From 和 To 该动画从 From 属性指定的值前进到 To 属性指定的值。
From 和 By 动画从 From 属性指定的值前进到由 From 属性和 By 属性之和指定的值。
To 该动画从已进行动画处理的属性的基值或前一个动画的输出值前进到 To 属性指定的值。
By 该动画从要进行动画处理的基值或前一个动画的输出值前进到上述值与 By 属性指定的值相加后的值。

注意

不要在同一个动画上同时设置 To 属性和 By 属性。

若要在两个以上的目标值之间使用内插方法或进行动画处理，请使用关键帧动画。 有关详细信息，请参阅关键帧动画概述。

有关将多个动画应用于单个属性的信息，请参阅关键帧动画概述。

下面的示例显示了在动画中设置 To、 By 和 From 属性的不同效果。

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