Setting AutoReverse true/false after Animation Starts.

Answer 1

This is because Animations are freezable objects. There is more information in the MSDN Documentation.

Once an animation is started, its properties cannot be changed, even in code-behind. You will need to stop the animation in your event handler, set the AutoReverse property, and restart it.

Answer 2

Store the current Values in local Variables then Set the AutoReverse true/false then Create the Clock then Assign back the stored values in the AnimationClock.