public void Padback_Grow(object sender, MouseEventArgs e) { double fromy; double toy; int duration = 300; fromy = 1; toy = 3.5; Animator.AnimatePenner(Padback, Rectangle.StrokeThicknessProperty, Tween.Equations.CubicEaseIn, fromy, toy, duration, OnAnimationComplete, OnAnimationComplete); }