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DoubleAnimation

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Animates the value of a Double between two target values by using linear interpolation over a specified Duration.

<DoubleAnimation   .../>

Managed Equivalent

DoubleAnimation

Remarks

An animation updates the value of a property over a period of time. An animation effect can be subtle, such as moving a Shape object a few pixels left or right, or dramatic, such as enlarging an object to 200 times its original size while spinning it and changing its color. To create an animation, you associate an animation with an object's property value.

The DoubleAnimation object creates a transition between two target values. To set the target values, use the object's From, To, and By properties. The following table summarizes how you can use the From, To, and By properties together or separately to determine an animation's target values.

For more information on basic concepts, see Animation Overview. Note that the Animation Overview topic is written primarily for users of the managed API, and may not have code examples or specific information that address the JavaScript API scenarios.

Properties specified

Resulting behavior

From

The animation progresses from the value of the From property to the base value of the property being animated.

From and To

The animation progresses from the value of the From property to the value of the To property.

From and By

The animation progresses from the value of the From property to the value of the sum of the From and By properties.

To

The animation progresses from the animated property's base value or a previous animation's output value to the value of the To property.

By

The animation progresses from the base value of the property being animated or a previous animation's output value to the sum of that value and the value of the By property.

If you set both the To and By properties, the To property takes precedence and the By property is ignored.

To use other interpolation methods or to animate between more than two target values, use a DoubleAnimationUsingKeyFrames object.

Example

The following example shows how to use a DoubleAnimation object to create a rectangle that fades in and out of view after it is loaded.

<Canvas
  xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
  <Rectangle
    x:Name="MyAnimatedRectangle"
    Width="100"
    Height="100"
    Fill="Blue">
    <Rectangle.Triggers>

      <!-- Animates the rectangle's opacity. -->
      <EventTrigger RoutedEvent="Rectangle.Loaded">
        <BeginStoryboard>
          <Storyboard>
            <DoubleAnimation
              Storyboard.TargetName="MyAnimatedRectangle"
              Storyboard.TargetProperty="Opacity"
              From="1.0" To="0.0" Duration="0:0:5" AutoReverse="True" RepeatBehavior="Forever" />
          </Storyboard>
        </BeginStoryboard>
      </EventTrigger>
    </Rectangle.Triggers>
  </Rectangle>
</Canvas>

The following example makes a rectangle fade from view when the user clicks it with the left mouse button. Unlike the previous example, the animation does not start automatically.

<Canvas
  xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
  <Canvas.Resources>
    <Storyboard x:Name="myStoryboard">
      <DoubleAnimation
        Storyboard.TargetName="MyAnimatedRectangle"
        Storyboard.TargetProperty="Opacity"
        From="1.0" To="0.0" Duration="0:0:5" 
        AutoReverse="True" />
    </Storyboard>  
  </Canvas.Resources>
  <Rectangle
    x:Name="MyAnimatedRectangle"
    Width="100"
    Height="100"
    Fill="Blue"
    MouseLeftButtonDown="startAnimation">
  </Rectangle>
</Canvas>

function startAnimation(sender, mouseEventArgs)
{
    // Retrieve the Storyboard and begin it.
    sender.findName("myStoryboard").begin();

}