SplineColorKeyFrame Class

Inheritance Hierarchy

System.Object
  System.Windows.DependencyObject
    System.Windows.Media.Animation.ColorKeyFrame
      System.Windows.Media.Animation.SplineColorKeyFrame

Syntax

'Declaration
Public NotInheritable Class SplineColorKeyFrame _
    Inherits ColorKeyFrame

public sealed class SplineColorKeyFrame : ColorKeyFrame

<SplineColorKeyFrame .../>

Constructors

	Name	Description
	SplineColorKeyFrame	Initializes a new instance of the SplineColorKeyFrame class.

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Properties

	Name	Description
	Dispatcher	Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
	KeySpline	Gets or sets the two control points that define animation progress for this key frame.
	KeyTime	Gets or sets the time at which the key frame's target Value should be reached. (Inherited from ColorKeyFrame.)
	Value	Gets or sets the key frame's target value. (Inherited from ColorKeyFrame.)

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Methods

	Name	Description
	CheckAccess	Determines whether the calling thread has access to this object. (Inherited from DependencyObject.)
	ClearValue	Clears the local value of a dependency property. (Inherited from DependencyObject.)
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GetAnimationBaseValue	Returns any base value established for a Silverlight dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	GetValue	Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	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.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Fields

	Name	Description
	KeySplineProperty	Identifies the KeySpline dependency property.

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Remarks

This class is used as part of a ColorKeyFrameCollection in conjunction with a ColorAnimationUsingKeyFrames to animate a Color property value along a set of key frames.

A key frame defines a segment of the ColorAnimationUsingKeyFrames to which it belongs. Each key frame has a target Value and a KeyTime. The KeyTime specifies the time at which the key frame's Value should be reached. A key frame animates from the target value of the previous key frame to its own target value. It starts when the previous key frame ends and ends when its own key time is reached.

Spline key frames like SplineColorKeyFrame create a variable transition between values that is determined by the KeySpline property. Splined interpolation can be used to achieve more realistic "real world" timing effects such as acceleration and deceleration.

A cubic Bezier curve is defined by a start point, an end point, and two control points. The KeySpline property of a spline key frame defines the two control points of a Bezier curve that extends from (0,0) to (1,1). The first control point controls the curve factor of the first half of the Bezier curve, and the second control point controls the curve factor of the second half of the Bezier segment. The resulting curve describes the rate of change for that spline key frame. The steeper the curve, the faster the key frame changes its values. As the curve gets flatter, the key frame changes its values more slowly.

Run the sample below to see how changing the KeySpline value effects the interpolation of the animation. Also, this sample demonstrates the effect of the KeySpline on the Bezier curve which represents the interpolation.

Run this sample

Examples

The following example uses the ColorAnimationUsingKeyFrames class to animate the Background property of a StackPanel. This animation uses three key frames in the following manner:

1. During the first two seconds, LinearColorKeyFrame gradually changes the color from green to red. Linear key frames like LinearColorKeyFrame create a smooth linear transition between values.

2. During the end of the next half second, DiscreteColorKeyFrame quickly changes the color from red to yellow. Discrete key frames like DiscreteColorKeyFrame create sudden changes between values; the animation occurs quickly and has no interpolation between values at all.

3. During the final two seconds, SplineColorKeyFrame changes the color again, this time from yellow back to green. Spline key frames like SplineColorKeyFrame create a variable transition between values according to the values of the KeySpline property. A KeySpline provides a way to alter the relationship of time versus value during the animation duration to be nonlinear, and in particular the relationship can be a curve that would be difficult to produce with individual key frames. In this example, the change in color begins slowly and speeds up exponentially toward the end of the time segment.

Run this sample

<StackPanel Background="White" x:Name="myStackPanel"
            Loaded="Start_Animation">
    <StackPanel.Resources>
        <Storyboard x:Name="colorStoryboard">
            <ColorAnimationUsingKeyFrames BeginTime="00:00:00" 
             Storyboard.TargetName="myStackPanel" 
             Storyboard.TargetProperty="(Panel.Background).(SolidColorBrush.Color)">

                <!-- Go from green to red in the first 2 seconds. LinearColorKeyFrame creates
        a smooth, linear animation between values. -->
                <LinearColorKeyFrame Value="Red" KeyTime="00:00:02" />

                <!-- In the next half second, go to yellow. DiscreteColorKeyFrame creates a 
        sudden jump between values. -->
                <DiscreteColorKeyFrame Value="Yellow" KeyTime="00:00:2.5" />

                <!-- In the final 2 seconds of the animation, go from yellow back to green. SplineColorKeyFrame 
        creates a variable transition between values depending on the KeySpline property. In this example,
        the animation starts off slow but toward the end of the time segment, it speeds up exponentially.-->
                <SplineColorKeyFrame Value="Green" KeyTime="00:00:4.5" KeySpline="0.6,0.0 0.9,0.00" />

            </ColorAnimationUsingKeyFrames>
        </Storyboard>
    </StackPanel.Resources>
</StackPanel>

' Start the animation when the object loads
Private Sub Start_Animation(ByVal sender As Object, ByVal e As EventArgs)
    colorStoryboard.Begin()
End Sub

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

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference