siverlight缓动函数（此示例来自msdn）

  <UserControl.Resources> <Storyboard x:Name="myStoryboard"> <DoubleAnimation From="30" To="200" Duration="00:00:3" Storyboard.TargetName="myRectangle" Storyboard.TargetProperty="Height"> <DoubleAnimation.EasingFunction> <BounceEase Bounces="4" EasingMode="EaseInOut" Bounciness="1.8" /> </DoubleAnimation.EasingFunction> </DoubleAnimation> </Storyboard> </UserControl.Resources> <Canvas x:Name="LayoutRoot" Background="White"><Rectangle x:Name="myRectangle" MouseLeftButtonDown="myRectangle_MouseLeftButtonDown" Fill="Blue" Width="200" Height="30" /> </Canvas>

 Bounces 属性指定弹跳次数并使用 Bounciness 属性指定弹跳程度（弹跳的弹性大小）。