如何在情节提要中为椭圆设置Targetproperty？

Question

I am learning storyboard in wpf C#. I have referred the msdn documentation on storyboard.For understanding, I created a simple application that just rotates an ellipse.

Here is my code..

<Ellipse  Name="myEllipse" Width="200" Height="200" Margin="266,42,51,78" 
          RenderTransformOrigin="0.5,0.5"  >
    <Ellipse.RenderTransform>
        <TransformGroup>
            <ScaleTransform/>
            <SkewTransform/>
            <RotateTransform Angle="0"/>
            <TranslateTransform/>
        </TransformGroup>
    </Ellipse.RenderTransform>
    <Ellipse.Fill>
        <ImageBrush ImageSource="circle.gif"></ImageBrush>
    </Ellipse.Fill>
</Ellipse>
// Button to animate the ellipse
<Button Width="60" Height="20" Margin="0,250,0,0" Content="Start">
    <Button.Triggers>
        <EventTrigger RoutedEvent="Button.Click">
            <BeginStoryboard>
                <Storyboard>
                    <DoubleAnimation Storyboard.TargetName="myEllipse"
                                     Storyboard.TargetProperty="Angle"
                                     From="0" To="360"
                                     AutoReverse="True" 
                                     RepeatBehavior="Forever"> 
                    </DoubleAnimation>        
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>
    </Button.Triggers>
</Button>

I want to set ellipse rotate transform angle of ellipse as double animation target property.As angle is not a property of the ellipse it throws an exception.Then I searched the SO and found a similar question and set targetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"

But that too didn't work. How can I set the angle as targetproperty ?

Thanks in advance..

Answer 1

In order to make

Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"

or simply

Storyboard.TargetProperty="RenderTransform.Angle"

work, you have to change the RenderTransform property from TransformGroup to RotateTransform :

<Ellipse.RenderTransform>
    <RotateTransform Angle="0"/>
</Ellipse.RenderTransform>

---

In case you need to keep the TransformGroup you have to write

Storyboard.TargetProperty="RenderTransform.Children[2].Angle"