小红色矩形绕百点 旋转的同时 红色矩形还要外扩。

<Grid x:Name="LayoutRoot" Background="White" >
<Canvas Background="Black" Name="circle">
<Canvas.Resources>
<Storyboard x:Name="circleTurn" >
<DoubleAnimation x:Name="circleDouble" Storyboard.TargetName="rect"
Storyboard.TargetProperty=" (UIElement.RenderTransform).(TransformGroup.Children)[0].(RotateTransform.Angle)"
Duration="0:0:3" RepeatBehavior="1x">
</DoubleAnimation>
</Storyboard>
<Storyboard x:Name="carRotateTurn" >
<DoubleAnimation x:Name="rectCarRotateDouble" Storyboard.TargetName="rectCar"
Storyboard.TargetProperty=" (UIElement.RenderTransform).(TransformGroup.Children)[0].(RotateTransform.Angle)"
Duration="0:0:3" RepeatBehavior="1x">
</DoubleAnimation>
</Storyboard>
<Storyboard x:Name="carMoveTurn" >
<PointAnimation x:Name="rectCarMovePoint" Storyboard.TargetName="rectCar"
Storyboard.TargetProperty="RenderTransformOrigin" From="-1.33,0.5" To="-7.33,0.5"
Duration="0:0:3" FillBehavior="Stop" RepeatBehavior="1x">
</PointAnimation>
</Storyboard>
</Canvas.Resources>
<Rectangle x:Name="rect" Height="2" Width="130" Fill="SkyBlue" Canvas.Left="170" Canvas.Top="149" RenderTransformOrigin="0.23,0.5">
<Rectangle.RenderTransform>
<TransformGroup>
<RotateTransform ></RotateTransform>
</TransformGroup>
</Rectangle.RenderTransform>
</Rectangle>
<Ellipse Fill="White" Width="10" Height="10" Canvas.Left="195" Canvas.Top="145"></Ellipse>
<Ellipse Stroke="SkyBlue" StrokeDashArray="5,5" Canvas.Left="100" Canvas.Top="50" StrokeDashCap="Flat" Width="200" Height="200" ></Ellipse>
<Rectangle Width="6" Height="6" Fill="Red" Name="rectCar" Canvas.Top="147" Canvas.Left="208" >
<Rectangle.RenderTransform>
<TransformGroup>
<RotateTransform ></RotateTransform>
</TransformGroup>
</Rectangle.RenderTransform>
</Rectangle>
</Canvas>
</Grid>