title: how to reset the angle property of RotateTransform
body: <p>I have a canvas include some element to show an robot arm. This arm can stretch out and draw back by animation.</p>
  
  <p>Now I need initialize the arm and keep collapsed status in some case(not by animation). So I need reset the angle property of RotateTransform.</p>
  
  <pre><code> &lt;Canvas x:Name="RobotArm_Left" Width="60" Height="10" RenderTransformOrigin="0.9167,0.5" Canvas.Top="62.5" Canvas.Left="12.5"&gt;
      &lt;Canvas.RenderTransform&gt;
          &lt;TransformGroup&gt;                                   
              &lt;RotateTransform x:Name="Rotate_RobotArm_Left" /&gt;                                    
          &lt;/TransformGroup&gt;
      &lt;/Canvas.RenderTransform&gt;
  &lt;/Canvas&gt;
  </code></pre>
  
  <p>I use two ways to set the angle:</p>
  
  <pre><code>((RotateTransform)page.FindName("Rotate_RobotArm_Left")).Angle=0; //0 is the init value
  ((RotateTransform)page.FindName("Rotate_RobotArm_Left")).SetValue(RotateTransform.AngleProperty, 0.0);
  </code></pre>
  
  <p>they all don't work. </p>
  
  <p>when I watch the value of ((RotateTransform)page.FindName("Rotate_RobotArm_Left")).Angle, it's -55.</p>
  
  <p>Is there one way to set the property?</p>
  
  <p>otherwise, before running animation, the angle property can be changed.But after animation,it cannot be changed.</p>
  
  <p>thanks.</p>