This method stops the animation clock from moving, but has no discernible effect if it is not active or currently paused. As a side effect, all associated children are also paused.
A storyboard can be paused, resumed, seeked, stopped, and removed if it is made controllable. To make a storyboard controllable in code, you must use the appropriate overload of the storyboard's Begin method and specify true to make it controllable. See How to: Control a Storyboard After It Starts for an example.
Beginning a Paused Storyboard
When you Begin a storyboard that was paused, it appears to resume and restart. That's not what actually happens, however: the Begin method actually replaces the paused Storyboard with a new unpaused version. Each time the Begin method is called, clock objects are created the storyboard. These clocks are distributed to the properties they animate. So, when the Begin method is called again, it doesn't restart its clocks; it replaces them with new clocks.