如何在运行时更改“ AnimationClock-timeline”属性？

Question

I used AnimationClock like this :

   DoubleAnimation ScrollAnimation = new DoubleAnimation();
   ....
     AnimationClock AnimClock = new AnimationClock();
     AnimClock = ScrollAnimation.CreateClock();
     TranslateTransform oTransform = (TranslateTransform)transGroup.Children[1];
     oTransform.ApplyAnimationClock(prop, AnimClock);
     AnimClock.Controller.SpeedRatio = ScrollSlider.Value; 
     AnimClock.Completed += ScrollClockController_Completed;
     oTransform.BeginAnimation(TranslateTransform.XProperty, ScrollAnimation);

My code works fine, But when I try to change AnimationClock-timeline properties ( RepeatBehavior or AutoReverse or etc.) after BeginAnimation the following error occurs:

AnimClock.Timeline.AutoReverse = true;

Cannot set a property on object 'System.Windows.Media.Animation.DoubleAnimation' because it is in a read-only state

Answer 1

"Although most Timeline properties are animatable and can be data bound, changing the property values of an active Timeline seems to have no effect. That's because, when a Timeline is begun, the timing system makes a copy of the Timeline and uses it to create a Clock object. Modifying the original has no effect on the system's copy.

For a Timeline to reflect changes, its clock must be regenerated and used to replace the previously created clock. Clocks are not regenerated for you automatically. The following are several ways to apply timeline changes:

If the timeline is or belongs to a Storyboard, you can make it reflect changes by reapplying its storyboard using a BeginStoryboard or the Begin method. This has the side effect of also restarting the animation. In code, you can use the Seek method to advance the storyboard back to its previous position.

If you applied an animation directly to a property using the BeginAnimation method, call the BeginAnimation method again and pass it the animation that has been modified.

If you are working directly at the clock level, create and apply a new set of clocks and use them to replace the previous set of generated clocks."

I found the answer at this page