DoubleAnimation Class

Definition

public ref class DoubleAnimation sealed : Timeline

/// [Windows.Foundation.Metadata.Activatable(65536, "Microsoft.UI.Xaml.WinUIContract")]
/// [Windows.Foundation.Metadata.ContractVersion(Microsoft.UI.Xaml.WinUIContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class DoubleAnimation final : Timeline

[Windows.Foundation.Metadata.Activatable(65536, "Microsoft.UI.Xaml.WinUIContract")]
[Windows.Foundation.Metadata.ContractVersion(typeof(Microsoft.UI.Xaml.WinUIContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class DoubleAnimation : Timeline

Public NotInheritable Class DoubleAnimation
Inherits Timeline

<DoubleAnimation />

Inheritance

Object Platform::Object IInspectable DependencyObject Timeline DoubleAnimation

Attributes

ActivatableAttribute ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Examples

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

<StackPanel>
    <StackPanel.Resources>
        <Storyboard x:Name="myStoryboard">
            <DoubleAnimation
          Storyboard.TargetName="MyAnimatedRectangle"
          Storyboard.TargetProperty="Opacity"
          From="1.0" To="0.0" Duration="0:0:3"
          AutoReverse="True" RepeatBehavior="Forever" />
        </Storyboard>
    </StackPanel.Resources>

    <Rectangle Loaded="Start_Animation" x:Name="MyAnimatedRectangle"
     Width="100" Height="100" Fill="Blue" />

</StackPanel>

// Start the animation when the object loads
private void Start_Animation(object sender, RoutedEventArgs e)
{
    myStoryboard.Begin();
}

<Canvas>
    <Canvas.Resources>
        <Storyboard x:Name="myStoryboard">

            <!-- Animate the TranslateTransform's X property
           from 0 to 350, then 50, then 200 over 10 seconds. -->
            <DoubleAnimationUsingKeyFrames
       Storyboard.TargetName="MyAnimatedTranslateTransform"
       Storyboard.TargetProperty="X"
       Duration="0:0:10" EnableDependentAnimation="True">

                <!-- Using a LinearDoubleKeyFrame, the rectangle moves 
           steadily from its starting position to 500 over 
           the first 3 seconds.  -->
                <LinearDoubleKeyFrame Value="500" KeyTime="0:0:3" />

                <!-- Using a DiscreteDoubleKeyFrame, the rectangle suddenly 
           appears at 400 after the fourth second of the animation. -->
                <DiscreteDoubleKeyFrame Value="400" KeyTime="0:0:4" />

                <!-- Using a SplineDoubleKeyFrame, the rectangle moves 
           back to its starting point. The animation starts out slowly at 
           first and then speeds up. This KeyFrame ends after the 6th
           second. -->
                <SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="0" KeyTime="0:0:6" />

            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
    </Canvas.Resources>

    <Rectangle PointerPressed="Pointer_Clicked" Fill="Blue"
 Width="50" Height="50">
        <Rectangle.RenderTransform>
            <TranslateTransform x:Name="MyAnimatedTranslateTransform" />
        </Rectangle.RenderTransform>
    </Rectangle>

</Canvas>

// Start the animation when the object loads
private void Start_Animation(object sender, RoutedEventArgs e)
{
    myStoryboard.Begin();
}

Remarks

Use DoubleAnimation to animate the property value of any dependency property that is of type Double.

Sometimes you'll need to use indirect property targeting in order to target a sub-property of another object that's the value of a property on the target. For example, in order to animate the X component of a RenderTransform of a UIElement, you need to reference some of the intermediate object-property values, until the last step in the indirect property path is truly a Double value, as is the case with TranslateTransform.X. The correct string to use for Storyboard.TargetProperty in this example is "(UIElement.RenderTransform).(TranslateTransform.X)". For more info on indirect property targeting and other storyboarded animation concepts, see Storyboarded animations.

A DoubleAnimation typically has at least one of the From, By or To properties set, but never all three.

• From only: The animation progresses from the value specified by the From property to the base value of the property being animated.
• From and To: The animation progresses from the value specified by the From property to the value specified by the To property.
• From and By: The animation progresses from the value specified by the From property to the value specified by the sum of the From and By properties.
• To only: The animation progresses from the animated property's base value or a previous animation's output value to the value specified by the To property.
• By only: 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 specified by the By property.

You can't animate the X and Y values of a Point using a DoubleAnimation, because these properties aren't dependency properties (Point is a structure and can't have dependency properties.) Instead, use PointAnimation to animate dependency properties that have a Point value.

You also can't use DoubleAnimation to animate int values or byte values. Instead, you'll have to use ObjectAnimationUsingKeyFrames, which won't give you an interpolation behavior, so you might need to define multiple keyframes to get a reasonably smooth animation. There aren't many UI-related dependency properties that use int values or byte values, so this shouldn't be a common scenario other than for custom properties.

The From, By or To properties of a DoubleAnimation aren't strictly a Double. Instead these are a Nullable for Double. The default value for these is null, not 0. That null value is how the animation system distinguishes that you haven't specifically set a value. Visual C++ component extensions (C++/CX) doesn't have a Nullable type, so it uses IReference instead.

Constructors

Properties

Methods

Events

Applies to

See also

• Timeline
• DoubleAnimationUsingKeyFrames
• Storyboarded animations
• XAML animation sample
• Double
• Double