DoubleAnimationUsingKeyFrames Class

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

Animates the value of a Double property along a set of KeyFrames.

Inheritance Hierarchy

System..::.Object
  System.Windows..::.DependencyObject
    System.Windows.Media.Animation..::.Timeline
      System.Windows.Media.Animation..::.DoubleAnimationUsingKeyFrames

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

Syntax

<ContentPropertyAttribute("KeyFrames", True)> _
Public NotInheritable Class DoubleAnimationUsingKeyFrames _
    Inherits Timeline

[ContentPropertyAttribute("KeyFrames", true)]
public sealed class DoubleAnimationUsingKeyFrames : Timeline

<DoubleAnimationUsingKeyFrames>
  oneOrMoreDoubleKeyFrames
</DoubleAnimationUsingKeyFrames>

XAML Values

• oneOrMoreDoubleKeyFrames
  One or more object elements that define the key frames for the animation. These object elements represent one of the classes deriving from DoubleKeyFrame. These are typically any combination of LinearDoubleKeyFrame, DiscreteDoubleKeyFrame, EasingDoubleKeyFrame, and SplineDoubleKeyFrame. Object elements defined here become members of the DoubleKeyFrameCollection collection when code accesses the KeyFrames property at run time.

The DoubleAnimationUsingKeyFrames type exposes the following members.

Constructors

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

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Properties

	Name	Description
	AutoReverse	Gets or sets a value that indicates whether the timeline plays in reverse after it completes a forward iteration. (Inherited from Timeline.)
	BeginTime	Gets or sets the time at which this Timeline should begin. (Inherited from Timeline.)
	Dispatcher	Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
	Duration	Gets or sets the length of time for which this timeline plays, not counting repetitions. (Inherited from Timeline.)
	FillBehavior	Gets or sets a value that specifies how the animation behaves after it reaches the end of its active period. (Inherited from Timeline.)
	KeyFrames	Gets the collection of DoubleKeyFrame objects that define the animation.
	RepeatBehavior	Gets or sets the repeating behavior of this timeline. (Inherited from Timeline.)
	SpeedRatio	Gets or sets the rate, relative to its parent, at which time progresses for this Timeline. (Inherited from Timeline.)

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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 Windows Phone 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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Events

	Name	Description
	Completed	Occurs when the Storyboard object has completed playing. (Inherited from Timeline.)

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Remarks

A key frame animation's target values are defined by its KeyFrames property, which contains a collection of DoubleKeyFrame objects. Each DoubleKeyFrame defines a segment of the animation with its own target Value and KeyTime. When the animation runs, it progresses from one key value to the next at the specified key times.

There are three types of DoubleKeyFrame classes, one for each supported interpolation method: LinearDoubleKeyFrame, DiscreteDoubleKeyFrame, and SplineDoubleKeyFrame.

Unlike a DoubleAnimation, a DoubleAnimationUsingKeyFrames can have more than two target values. You can also control the interpolation method of individual DoubleKeyFrame segments.

When declaring a DoubleAnimationUsingKeyFrames in XAML, the order of the DoubleKeyFrame object elements is not significant, because the KeyTime controls the timing and therefore the order in which the key frames are executed. However, it is good markup style to keep the element order the same as the KeyTime sequence order.

Examples

The following example moves a rectangle across a screen. The example uses the DoubleAnimationUsingKeyFrames 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.

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

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

<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">

                <!-- 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>

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

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

System.Windows.Media.Animation Namespace

Other Resources

Animations, motion, and output for Windows Phone