DiscreteColorKeyFrame Class

DiscreteColorKeyFrame Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Animates from the Color value of the previous key frame to its own Value using discrete values.

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

Namespace:  System.Windows.Media.Animation
Assembly:  System.Windows (in System.Windows.dll)
XMLNS for XAML: Not mapped to an xmlns.

public sealed class DiscreteColorKeyFrame : ColorKeyFrame
<DiscreteColorKeyFrame .../>

The DiscreteColorKeyFrame type exposes the following members.

  NameDescription
Public methodDiscreteColorKeyFrameInitializes a new instance of the DiscreteColorKeyFrame class.
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  NameDescription
Public propertyDispatcherGets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
Public propertyKeyTimeGets or sets the time at which the key frame's target Value should be reached. (Inherited from ColorKeyFrame.)
Public propertyValueGets or sets the key frame's target value. (Inherited from ColorKeyFrame.)
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  NameDescription
Public methodCheckAccessDetermines whether the calling thread has access to this object. (Inherited from DependencyObject.)
Public methodClearValueClears the local value of a dependency property. (Inherited from DependencyObject.)
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetAnimationBaseValueReturns any base value established for a Windows Phone dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodGetValueReturns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodReadLocalValueReturns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
Public methodSetValueSets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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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.

Discrete key frames such as DiscreteColorKeyFrame create sudden "jumps" between values (no interpolation). In other words, the animated property does not change until the key frame's key time is reached, at which point the animated property goes suddenly to the target value.

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.


<StackPanel Background="Transparent" 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 void Start_Animation(object sender, EventArgs e)
{
    colorStoryboard.Begin();
}


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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

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