Need help applying animation in transform group in wpf

Question

I have a piece of xaml that applies a scale transform and a rotatetransform.

        <Image.RenderTransform>
            <TransformGroup>
                <RotateTransform Angle="0" x:Name="RotateTransform"/>
                <TranslateTransform X="0" Y="0"/>
                <ScaleTransform ScaleX="2" ScaleY="2"/>
            </TransformGroup>
        </Image.RenderTransform>

I also have a storyboard that needs to accesss RotateTransform like so:

        <Storyboard x:Key="Storyboard"
                Storyboard.TargetProperty="(RenderTransform).(RotateTransform.Angle)"
                Storyboard.TargetName="RotateTransform">
        <DoubleAnimation From="0" To="360" RepeatBehavior="Forever" SpeedRatio="0.25" />
    </Storyboard>

However I can not get the image to rotate, but it does scale up. Does anyone have suggestions to fix the problem?

Edit: I did figure out that i can use

    <Storyboard x:Key="Storyboard"
                Storyboard.TargetProperty="(Image.RenderTransform).Children[0].Angle"
                Storyboard.TargetName="ContentImage">
        <DoubleAnimation From="0" To="360" RepeatBehavior="Forever" SpeedRatio="0.25" />
    </Storyboard>

And call the animation by the array position, but why is it not possible to actually call the transform property's angle property automatically by x:Name?

Answer 1

A RotateTransform does not have RenderTransform property, so you can't animate RenderTransform.Angle.

The animation would have to target the Angle property directly. Moreover, you would usually apply the TargetName and TargetProperty properties to the DoubleAnimation, not to the Storyboard. You would also set the Duration of the animation instead of applying a SpeedRatio for the default duration of one second.

<Storyboard>
    <DoubleAnimation
        Storyboard.TargetName="RotateTransform"
        Storyboard.TargetProperty="Angle"
        From="0" To="360" RepeatBehavior="Forever" Duration="0:0:4"/>
</Storyboard>