Advanced Animations (Key-Frame Animations)
Up to now, the examples in this QuickStart have shown animating between two values. (These are called From/To/By animations.) Key-frame animations let you use more than two target values and control an animation's interpolation method. By specifying multiple values to animate, you can make more complex animations. By specifying the animation's interpolation (specifically, by using the KeySpline property), you can control the acceleration of an animation.
The following example shows how to use a key-frame animation to animate the height of a rectangle. To try this example, click the rectangle to see the effect.