How to rotate a image in xaml/c#

Question

Im trying to rotate a <Image> of an arrow (placed in the middle of a 40x40 image). By what I remember from graphics class i need to first translate the image back to its center, rotate and then translate back:

            TranslateTransform tTrans = new TranslateTransform();
            tTrans.X -= 20;
            tTrans.X -= 20;

            RotateTransform rTrans = new RotateTransform();
            rTrans.Angle = 60;

            TranslateTransform t2Trans = new TranslateTransform();
            tTrans.X += 20;
            tTrans.X += 20;

            imgWind.RenderTransform = ?;

Anyone got a good idea on how i can apply the transformations?

Answer 1

You can simply use

imgWind.RenderTransform = new RotateTransform(){ CenterX = 0.5, CenterY = 0.5, Angle = 45 };

Or in XAML:

<UIElement RenderTransformOrigin="0.5,0.5">
      <UIElement.RenderTransform>
      <RotateTransform CenterX="0.5" CenterY="0.5" Angle="45" />
      </UIElement.RenderTransform>
</UIElement>

By setting the CenterX and CenterY you don't have to translate before and after. In WPF (or silverlight for that matter) the transforms will take care of that themselfs.