Why doesn't this rotate? (WPF Storyboard)

Question

I'm trying to learn how to implement Storyboards in the code-behind.   I have a simple rotation of some label text that works fine in XAML . . .

    <Storyboard x:Key="StoryboardRotation">
                      <DoubleAnimation
                      Storyboard.TargetName="lblHello"
                      Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
                      From="0"
                      To="360"
                      Duration="0:0:0.5"
                      RepeatBehavior="4x" />
    </Storyboard>

But when I try to implement it in a button handler in the code-behind it doesn't rotate (nothing seems to happen) . . .

            Storyboard sb = new Storyboard();

            DoubleAnimation da_AngleAnimation
               = new DoubleAnimation();

            da_AngleAnimation.From = 360;
            da_AngleAnimation.To = 0;
            da_AngleAnimation.Duration
              = new Duration(new TimeSpan(0, 0, 0, 0, 500));
            da_AngleAnimation.RepeatBehavior = new RepeatBehavior(4);

            PropertyPath PropP = new PropertyPath(RotateTransform.AngleProperty);

            Storyboard.SetTargetName(da_AngleAnimation, lblHello.Name);
            Storyboard.SetTargetProperty(da_AngleAnimation,PropP);

            sb.Children.Add(da_AngleAnimation);

            this.BeginStoryboard(sb);

What am I doing wrong?   Thanks in advance!!!

Peter · Answer

Galasoft is where I got the original code. But I couldn't get his example to work without errors  even when I downloaded his example code. But that's OK - I rewrote the app from scratch and figured out a solution on my own - it's based on the recognition that RotateTransform is not a direct property of a TextBlock. To make the rotation angle accessible first do this in the XAML: Then in the code-behind you can do it this . . . Storyboard sb = new Storyboard(); // Create a DoubleAnimation to animate the angle . . . DoubleAnimation myDoubleAnimation = new DoubleAnimation(); myDoubleAnimation.From = 0; myDoubleAnimation.To = 180; myDoubleAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(2500)); Storyboard.SetTargetName(myDoubleAnimation rtAngle); PropertyPath PropP = new PropertyPath(RotateTransform.AngleProperty); Storyboard.SetTargetProperty(myDoubleAnimation PropP); sb.Children.Add(myDoubleAnimation); sb.Begin(this.textBlock1); Note that my original code also had an error in the invocation of the animation now fixed.

Sanjay Chauhan · Answer

Hi Take the reference of this article http://www.galasoft.ch/mydotnet/articles/article-2006102701.aspx

Why doesn't this rotate? (WPF, Storyboard)