WPF Setting ScaleTransform values

[Greg Keogh]

I have an animation that zooms a logo image into view. The Storyboard (not
shown) begins and animates the Angle, ScaleX and ScaleY values creating a
nice spin and zoom-out effect. The trouble is, I can't set the Scale values
back to 0.0 again so that the image is hidden and the animation is ready to
being again. The control is defined like this:

 

<Image x:Name="imgWatermark" Width="500" Height="375">

  <Image.RenderTransform>

    <TransformGroup>

      <RotateTransform Angle="0" CenterX="250" CenterY="187" />

      <ScaleTransform CenterX="250" CenterY="187" ScaleX="0.0"
ScaleY="0.0"/>

    </TransformGroup>

  </Image.RenderTransform>

</Image>

 

Later I do this to "hide" the image again ready for another zoom out.

 

ScaleTransform st =
((TransformGroup)imgWatermark.RenderTransform).Children[1] as
ScaleTransform;

st.ScaleX = 0.0;

st.ScaleY = 0.0;

 

However, this code results in no visible effect. What trick am I missing?

 

Greg