PointAnimationUsingKeyFrames.KeyFrames Property
Gets or sets the collection of PointKeyFrame objects that define the animation.
Assembly: PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
<object> <PointKeyFrameCollection .../> </object>
Property Value
Type: System.Windows.Media.Animation.PointKeyFrameCollectionThe collection of PointKeyFrame objects that define the animation. The default value is Empty.
This example shows how to use the PointAnimationUsingKeyFrames class to animate a Point.
The following 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:
During the first half second, 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 like LinearPointKeyFrame create a smooth linear interpolation between values.
During the end of the next half second, 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.
During the final two seconds, 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.
Imports System Imports System.Windows Imports System.Windows.Controls Imports System.Windows.Shapes Imports System.Windows.Media.Animation Imports System.Windows.Media Namespace Microsoft.Samples.KeyFrameExamples ''' <summary> ''' This example shows how to use the PointAnimationUsingKeyFrames class ''' to animate the position of an object. ''' </summary> Public Class PointAnimationUsingKeyFramesExample Inherits Page Public Sub New() Title = "PointAnimationUsingKeyFrames Example" Background = Brushes.White Margin = New Thickness(20) ' Create a NameScope for this page so that ' Storyboards can be used. NameScope.SetNameScope(Me, New NameScope()) ' Create an EllipseGeometry. Dim myAnimatedEllipseGeometry As New EllipseGeometry(New Point(200,100), 15, 15) ' Assign the EllipseGeometry a name so that ' it can be targeted by a Storyboard. Me.RegisterName("MyAnimatedEllipseGeometry", myAnimatedEllipseGeometry) ' Create a Path element to display the geometry. Dim aPath As New Path() aPath.Fill = Brushes.Blue aPath.Data = myAnimatedEllipseGeometry ' Create a Canvas to contain the path. Dim containerCanvas As New Canvas() containerCanvas.Width = 500 containerCanvas.Height = 400 containerCanvas.Children.Add(aPath) ' Create a PointAnimationUsingKeyFrames to ' animate the EllipseGeometry. Dim centerPointAnimation As New PointAnimationUsingKeyFrames() centerPointAnimation.Duration = TimeSpan.FromSeconds(5) ' Animate from the starting position to (100,300) ' over the first half-second using linear ' interpolation. centerPointAnimation.KeyFrames.Add(New LinearPointKeyFrame(New Point(100, 300), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(0.5)))) ' KeyTime - Target value (KeyValue) ' Animate from (100,300) (the value of the previous key frame) ' to (400,300) at 1 second using discrete interpolation. ' Because the interpolation is discrete, the ellipse will appear ' to "jump" to (400,300) at 1 second. centerPointAnimation.KeyFrames.Add(New DiscretePointKeyFrame(New Point(400, 300), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(1)))) ' KeyTime - Target value (KeyValue) ' Animate from (400,300) (the value of the previous key frame) to (200,100) ' over two seconds, starting at 1 second (the key time of the ' last key frame) and ending at 3 seconds. centerPointAnimation.KeyFrames.Add(New SplinePointKeyFrame(New Point(200, 100), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3)), New KeySpline(0.6, 0.0, 0.9, 0.0))) ' KeySpline - KeyTime - Target value (KeyValue) ' Set the animation to repeat forever. centerPointAnimation.RepeatBehavior = RepeatBehavior.Forever ' Set the animation to target the Center property ' of the object named "MyAnimatedEllipseGeometry". Storyboard.SetTargetName(centerPointAnimation, "MyAnimatedEllipseGeometry") Storyboard.SetTargetProperty(centerPointAnimation, New PropertyPath(EllipseGeometry.CenterProperty)) ' Create a storyboard to apply the animation. Dim ellipseStoryboard As New Storyboard() ellipseStoryboard.Children.Add(centerPointAnimation) ' Start the storyboard when the Path loads. AddHandler aPath.Loaded, Sub(sender As Object, e As RoutedEventArgs) ellipseStoryboard.Begin(Me) Content = containerCanvas End Sub End Class End Namespace
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Background="White" Margin="20"> <Canvas Width="400" Height="400"> <Path Fill="Blue"> <Path.Data> <!-- Describes an ellipse. --> <EllipseGeometry x:Name="MyAnimatedEllipseGeometry" Center="200,100" RadiusX="15" RadiusY="15" /> </Path.Data> <Path.Triggers> <EventTrigger RoutedEvent="Path.Loaded"> <BeginStoryboard> <Storyboard> <!-- 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"> <!-- 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> </BeginStoryboard> </EventTrigger> </Path.Triggers> </Path> </Canvas> </Page>
For the complete sample, see KeyFrame Animation Sample.
For consistency with other animation examples, the code versions of this example use a Storyboard object to apply the PointAnimationUsingKeyFrames. However, when applying a single animation in code, it's simpler to use the BeginAnimation method instead of using a Storyboard. For an example, see How to: Animate a Property Without Using a Storyboard.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.