EasingDoubleKeyFrame Class

<StackPanel x:Name="LayoutRoot" Background="White">
    <StackPanel.Resources>
        <Storyboard x:Name="myStoryboard">
            <DoubleAnimationUsingKeyFrames
             Storyboard.TargetProperty="Height"
             Storyboard.TargetName="myRectangle">

                <!-- This keyframe animates the ellipse up to the crest 
                     where it slows down and stops. -->
                <EasingDoubleKeyFrame Value="30" KeyTime="00:00:02">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <CubicEase EasingMode="EaseOut"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>

                <!-- This keyframe animates the ellipse back down and makes
                     it bounce. -->
                <EasingDoubleKeyFrame Value="200" KeyTime="00:00:06">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <BounceEase Bounces="5" EasingMode="EaseOut"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>

            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
    </StackPanel.Resources>

    <Rectangle x:Name="myRectangle" MouseLeftButtonDown="Mouse_Clicked" 
     Fill="Blue" Width="200" Height="200" />
</StackPanel>

' When the user clicks the rectangle, the animation
' begins. 
Private Sub Mouse_Clicked(ByVal sender As Object, ByVal e As MouseEventArgs)
    myStoryboard.Begin()
End Sub

// When the user clicks the rectangle, the animation
// begins. 
private void Mouse_Clicked(object sender, MouseEventArgs e)
{
    myStoryboard.Begin();
}