If the targeted properties are already animated, they are replaced using the specified handoff behavior.
To interactively control this storyboard, you must specify the same containingObject when calling the interactive methods that you used to begin the storyboard
When this method is called, Clock objects are created for the storyboard and any timelines it contains. These clocks are stored with containingObject.
Beginning a storyboard triggers the CurrentStateInvalidated and CurrentGlobalSpeedInvalidated events.
Using the Compose HandoffBehavior
When you apply a Storyboard, AnimationTimeline, or AnimationClock to a property using the Compose HandoffBehavior, any Clock objects previously associated with that property continue to consume system resources; the timing system does not remove these clocks automatically.
To avoid performance issues when you apply a large number of clocks using Compose, you should remove composing clocks from the animated property after they complete. There are several ways to remove a clock.
This is primarily an issue for animations on objects that have a long lifetime. When an object is garbage collected, its clocks are also disconnected and garbage collected.
For more information about clock objects, see Animation and Timing System Overview.