ObjectAnimationUsingKeyFrames Class
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ObjectAnimationUsingKeyFrames Class

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

Animates the value of an Object property along a set of KeyFrames over a specified Duration.

System.Object
  System.Windows.DependencyObject
    System.Windows.Media.Animation.Timeline
      System.Windows.Media.Animation.ObjectAnimationUsingKeyFrames

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

[ContentPropertyAttribute("KeyFrames", true)]
public sealed class ObjectAnimationUsingKeyFrames : Timeline
<ObjectAnimationUsingKeyFrames>oneOrMoreDiscreteObjectKeyFrames</ObjectAnimationUsingKeyFrames>

XAML Values

oneOrMoreDiscreteObjectKeyFrames

One or more DiscreteObjectKeyFrame object elements that define the key frames for the animation.

The ObjectAnimationUsingKeyFrames type exposes the following members.

  NameDescription
Public methodObjectAnimationUsingKeyFramesInitializes a new instance of the ObjectAnimationUsingKeyFrames class.
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  NameDescription
Public propertyAutoReverseGets or sets a value that indicates whether the timeline plays in reverse after it completes a forward iteration. (Inherited from Timeline.)
Public propertyBeginTimeGets or sets the time at which this Timeline should begin. (Inherited from Timeline.)
Public propertyDispatcherGets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
Public propertyDurationGets or sets the length of time for which this timeline plays, not counting repetitions. (Inherited from Timeline.)
Public propertyFillBehaviorGets or sets a value that specifies how the animation behaves after it reaches the end of its active period. (Inherited from Timeline.)
Public propertyKeyFramesGets the collection of ObjectKeyFrame objects that define the animation.
Public propertyRepeatBehaviorGets or sets the repeating behavior of this timeline. (Inherited from Timeline.)
Public propertySpeedRatioGets or sets the rate, relative to its parent, at which time progresses for this Timeline. (Inherited from Timeline.)
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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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  NameDescription
Public eventCompletedOccurs when the Storyboard object has completed playing. (Inherited from Timeline.)
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NoteNote:

Only discrete interpolation (DiscreteObjectKeyFrame) is available for use with ObjectAnimationUsingKeyFrames, which swaps object values according to a specified timeline. Other types of interpolation are too problematic to apply to objects.

The following example uses the ObjectAnimationUsingKeyFrames class to animate the Fill property of a Rectangle. This animation uses two key frames in the following manner:

  1. Using a DiscreteObjectKeyFrame, the Fill property of the Rectangle suddenly changes to a LinearGradientBrush after the first two seconds of the animation.

  2. After the third second of the animation, the Fill property is suddenly changed to a different LinearGradientBrush, which remains until the end of the animation (4 seconds total).


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

            <!-- ObjectAnimationUsingKeyFrames is used to animate properties that take
         an object as a value. This animation lasts for 4 seconds using 3 KeyFrames which
         swap different brush objects at regular intervals, making the background of the Page
         change. -->
            <ObjectAnimationUsingKeyFrames
         Storyboard.TargetName="animatedRectangle"
         Storyboard.TargetProperty="Fill"
         Duration="0:0:4" RepeatBehavior="Forever">
                <ObjectAnimationUsingKeyFrames.KeyFrames>

                    <!-- Note: Only discrete interpolation (DiscreteObjectKeyFrame) is available for 
                use with ObjectAnimationUsingKeyFrames which merely swaps objects according to
                a specified timeline. Other types of interpolation are too problematic to apply
                to objects.  -->
                    <!-- Using a DiscreteObjectKeyFrame, the Fill property of the Rectangle suddenly  
                changes to a LinearGradientBrush after the first two seconds of the animation. -->
                    <DiscreteObjectKeyFrame KeyTime="0:0:2">
                        <DiscreteObjectKeyFrame.Value>
                            <LinearGradientBrush>
                                <LinearGradientBrush.GradientStops>
                                    <GradientStop Color="Yellow" Offset="0.0" />
                                    <GradientStop Color="Orange" Offset="0.5" />
                                    <GradientStop Color="Red" Offset="1.0" />
                                </LinearGradientBrush.GradientStops>
                            </LinearGradientBrush>
                        </DiscreteObjectKeyFrame.Value>
                    </DiscreteObjectKeyFrame>

                    <!-- After the third second of the animation, the Fill property is suddenly changed 
                to a different LinearGradientBrush which remains until the end of the animation 
                (4 seconds total). -->
                    <DiscreteObjectKeyFrame KeyTime="0:0:3">
                        <DiscreteObjectKeyFrame.Value>
                            <RadialGradientBrush GradientOrigin="0.75,0.25">
                                <RadialGradientBrush.GradientStops>
                                    <GradientStop Color="White" Offset="0.0" />
                                    <GradientStop Color="MediumBlue" Offset="0.5" />
                                    <GradientStop Color="Black" Offset="1.0" />
                                </RadialGradientBrush.GradientStops>
                            </RadialGradientBrush>
                        </DiscreteObjectKeyFrame.Value>
                    </DiscreteObjectKeyFrame>

                </ObjectAnimationUsingKeyFrames.KeyFrames>
            </ObjectAnimationUsingKeyFrames>
        </Storyboard>
    </StackPanel.Resources>

    <!-- The Fill property of this rectangle is animated. -->
    <Rectangle x:Name="animatedRectangle" Loaded="Rectangle_Loaded" Width="300" Height="300" />

</StackPanel>



// When the rectangle loads, begin the animation.
private void Rectangle_Loaded(object sender, EventArgs e)
{
    myStoryboard.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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