SplinePointKeyFrame class

Applies to Windows and Windows Phone

Animates from the Point value of the previous key frame to its own Value using splined interpolation.

Inheritance

Object
  DependencyObject
    PointKeyFrame
      SplinePointKeyFrame

Syntax


public sealed class SplinePointKeyFrame : PointKeyFrame


<SplinePointKeyFrame .../>

Attributes

[MarshalingBehavior(Agile)]
[Threading(Both)]
[Version(0x06020000)]
[WebHostHidden()]

Members

The SplinePointKeyFrame class has these types of members:

Constructors

The SplinePointKeyFrame class has these constructors.

ConstructorDescription
SplinePointKeyFrame Initializes a new instance of the SplinePointKeyFrame class.

 

Methods

The SplinePointKeyFrame class has these methods. It also inherits methods from the Object class.

MethodDescription
ClearValue Clears the local value of a dependency property. (Inherited from DependencyObject)
GetAnimationBaseValue Returns any base value established for a dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject)
GetValue Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject)
ReadLocalValue Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject)
SetValue Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject)

 

Properties

The SplinePointKeyFrame class has these properties.

PropertyAccess typeDescription

Dispatcher

Read-onlyGets the CoreDispatcher that this object is associated with. (Inherited from DependencyObject)

KeySpline

Read/writeGets or sets the two control points that define animation progress for this key frame.

KeySplineProperty

Read-onlyIdentifies the KeySpline dependency property.

KeyTime

Read/writeGets or sets the time at which the key frame's target Value should be reached. (Inherited from PointKeyFrame)

Value

Read/writeGets or sets the key frame's target value. (Inherited from PointKeyFrame)

 

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 can mix discrete, linear, and spline keyframes in the same keyframe collection.

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

Examples

This XAML example moves an ellipse along a triangular path. The example uses the PointAnimationUsingKeyFrames class to animate the Center property of an EllipseGeometry. This animation uses three key frames in the following manner:

  1. During the first half second, it uses an instance of the LinearPointKeyFrame class to move the ellipse along a path at a steady rate from its starting position. Linear key frames such as LinearPointKeyFrame create a smooth linear interpolation between values.

  2. During the end of the next half second, it uses an instance of the DiscretePointKeyFrame class to suddenly move the ellipse along the path to the next position. Discrete key frames like DiscretePointKeyFrame create sudden jumps between values.

  3. During the final two seconds, it uses an instance of the SplinePointKeyFrame class to move the ellipse back to its starting position. Spline key frames like SplinePointKeyFrame create a variable transition between values according to the values of the KeySpline property. In this example, the animation begins slowly and speeds up exponentially toward the end of the time segment.


<Canvas Width="400" Height="300">
    <Canvas.Resources>
        <Storyboard x:Name="myStoryboard">

            <!-- Animating the Center property uses 3 KeyFrames, which animate
             the ellipse allong a triangular path. -->
            <PointAnimationUsingKeyFrames
          Storyboard.TargetProperty="Center"
          Storyboard.TargetName="MyAnimatedEllipseGeometry"
          Duration="0:0:5" RepeatBehavior="Forever" EnableDependentAnimation="True">

                <!-- Over the first half second, Using a LinearPointKeyFrame, the ellipse 
               moves steadily from its starting position along the first line of the 
               trianglar path.  -->
                <LinearPointKeyFrame KeyTime="0:0:0.5" Value="100,300" />

                <!-- Using a DiscretePointKeyFrame, the ellipse suddenly changes position
               after the first second of the animation. -->
                <DiscretePointKeyFrame KeyTime="0:0:1" Value="400,300" />

                <!-- Using a SplinePointKeyFrame, the ellipse moves back to its starting
               position. It moves slowly at first and then speeds up. This key frame 
               takes 2 seconds to complete. -->
                <SplinePointKeyFrame KeySpline="0.6,0.0 0.9,0.00" 
                 KeyTime="0:0:3" Value="200,100" />
            </PointAnimationUsingKeyFrames>
        </Storyboard>
    </Canvas.Resources>
    <Path Fill="Blue" Loaded="Start_Animation">
        <Path.Data>

            <!-- Describes an ellipse. -->
            <EllipseGeometry x:Name="MyAnimatedEllipseGeometry"
             Center="200,100" RadiusX="15" RadiusY="15" />
        </Path.Data>
    </Path>
</Canvas>



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


Requirements

Minimum supported client

Windows 8 [Windows Store apps only]

Minimum supported server

Windows Server 2012 [Windows Store apps only]

Minimum supported phone

Windows Phone 8.1 [Windows Runtime apps only]

Namespace

Windows.UI.Xaml.Media.Animation
Windows::UI::Xaml::Media::Animation [C++]

Metadata

Windows.winmd

See also

Storyboarded animations
Key-frame animations and easing function animations
PointKeyFrame
PointAnimationUsingKeyFrames
KeyTime
Value

 

 

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