Question

I managed to developp a storyboard to translate an object from its initial position to another position, but when I trigger the storyboard a second time, or call another storyboard, the object always translate from its initial position, not from the new one established after the first translation. How to change it ?

My code :

 TranslateTransform animatedTranslateTransform = new TranslateTransform();
 this.RegisterName("slide", animatedTranslateTransform);
 TransformGroup transformGroup = new TransformGroup();
 transformGroup.Children.Add(animatedTranslateTransform);
 _button.RenderTransform = transformGroup;

 //translate Y
 DoubleAnimation slideDown = new DoubleAnimation(20, TimeSpan.FromSeconds(1.0));
 Storyboard.SetTargetName(slideDown, "slide");
 Storyboard.SetTargetProperty(slideDown, new PropertyPath(TranslateTransform.YProperty));
 storyBoardSlideDown.Children.Add(slideDown);

Answer 1

Use DoubleAnimation.By instead of DoubleAnimation.To. From MSDN:

The animation progresses from the base value of the property being
animated or a previous animation’s output value to the sum of that
value and the value specified by the By property

Write

DoubleAnimation slideDown =
    new DoubleAnimation { By = 20, Duration = TimeSpan.FromSeconds(1.0) };