LinearDoubleKeyFrame Class

Definition

public ref class LinearDoubleKeyFrame sealed : DoubleKeyFrame

/// [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 LinearDoubleKeyFrame final : DoubleKeyFrame

[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 LinearDoubleKeyFrame : DoubleKeyFrame

Public NotInheritable Class LinearDoubleKeyFrame
Inherits DoubleKeyFrame

<LinearDoubleKeyFrame .../>

Inheritance

Object Platform::Object IInspectable DependencyObject DoubleKeyFrame LinearDoubleKeyFrame

Attributes

ActivatableAttribute ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Examples

This XAML example moves a rectangle across a screen. The example uses the LinearDoubleKeyFrame class to animate the X property of a TranslateTransform applied to a Rectangle. This animation uses three key frames in the following manner:

1. During the first three seconds, it uses an instance of the LinearDoubleKeyFrame class to move the rectangle along a path at a steady rate from its starting position to the 500 position. Linear key frames like LinearDoubleKeyFrame create a smooth linear transition between values.
2. At the end of the fourth second, it uses an instance of the DiscreteDoubleKeyFrame class to suddenly move the rectangle to the next position. Discrete key frames like DiscreteDoubleKeyFrame create sudden jumps between values. In this example, the rectangle is at the starting position and then suddenly appears at the 500 position.
3. In the final two seconds, it uses an instance of the SplineDoubleKeyFrame class to move the rectangle back to its starting position. Spline key frames like SplineDoubleKeyFrame create a variable transition between values according to the value of the KeySpline property. In this example, the rectangle begins by moving slowly and then speeds up exponentially toward the end of the time segment.

<StackPanel>
    <StackPanel.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>
    </StackPanel.Resources>
    <Rectangle Fill="Blue" Width="50" Height="50" Loaded="Start_Animation">
        <Rectangle.RenderTransform>
            <TranslateTransform x:Name="MyAnimatedTranslateTransform" 
             X="0" Y="0" />
        </Rectangle.RenderTransform>
    </Rectangle>
</StackPanel>

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

Remarks

Key-frame animations permit more than one target value that is reached at a point along the animation timeline. In other words each key frame can specify a different intermediate value, and the last key frame reached is the final animation value. By specifying multiple values to animate, you can make more complex animations. You'd typically have at least two keyframes in a DoubleAnimationUsingKeyFrames with LinearDoubleKeyFrame, otherwise a DoubleAnimation would have been simpler.

For more info on how to use key-frame animations, see Key-frame animations and easing function animations.

Constructors

Properties

Methods

Applies to

See also

• DoubleKeyFrame
• DoubleAnimationUsingKeyFrames
• DoubleKeyFrameCollection
• KeyTime
• Value
• Storyboarded animations
• Key-frame animations and easing function animations