一个简单的WPF平移动画不执行也不报错，请高手来看看解决思路

一个简单的WPF平移动画不执行也不报错，请高手来看看
刚学WPF动画部分，用code写的动画不知道为什么不会执行，但是也没报任何错误。功能仅仅只是让一个矩形平移一段距离，代码如下。在线求解！！

XAML代码：

  <Rectangle Width="200" Height="100" Fill="#FFF70505" Name="rectangle" />
  <Button Content="Button" Height="25" Width="78" Click="Button_Click">

C# 代码：
  private void Button_Click(object sender, RoutedEventArgs e)
  {
  rectangle.RenderTransform = new TranslateTransform();
  DoubleAnimation animation = new DoubleAnimation();
  animation.To = 50;
  animation.Duration = new System.Windows.Duration(TimeSpan.FromSeconds(2));

  Storyboard storyboard = new Storyboard();
  Storyboard.SetTarget(animation, rectangle.RenderTransform);
  Storyboard.SetTargetProperty(animation, new PropertyPath(TranslateTransform.XProperty));
  storyboard.Children.Add(animation);

  storyboard.Begin();
  }

[解决办法]
下面代码测试过，是可行的：

C# code

 rectangle.RenderTransform = new TranslateTransform();            DoubleAnimation animation = new DoubleAnimation();            animation.To = 250;            animation.Duration = new System.Windows.Duration(TimeSpan.FromSeconds(2));            Storyboard storyboard = new Storyboard();            Storyboard.SetTarget(animation, rectangle);            Storyboard.SetTargetProperty(animation, new PropertyPath("(UIElement.RenderTransform).(TranslateTransform.X)"));            storyboard.Children.Add(animation);            storyboard.Begin();