c# - 使用 C# for WP 的简单动画

Question

我正在尝试使用代码创建一个简单的动画。我复制粘贴了 msdn 的相同代码，如下所示：

public MainPage()
{
    InitializeComponent();
    Rectangle myRectangle = new Rectangle();
    myRectangle.Width = 200;
    myRectangle.Height = 200;
    Color myColor = Color.FromArgb(255, 255, 0, 0);
    SolidColorBrush myBrush = new SolidColorBrush();
    myBrush.Color = myColor;
    myRectangle.Fill = myBrush;

    // Add the rectangle to the tree.
    LayoutRoot.Children.Add(myRectangle);

    // Create a duration of 2 seconds.
    Duration duration = new Duration(TimeSpan.FromSeconds(2));

    // Create two DoubleAnimations and set their properties.
    DoubleAnimation myDoubleAnimation1 = new DoubleAnimation();
    DoubleAnimation myDoubleAnimation2 = new DoubleAnimation();

    myDoubleAnimation1.Duration = duration;
    myDoubleAnimation2.Duration = duration;

    Storyboard sb = new Storyboard();
    sb.Duration = duration;

    sb.Children.Add(myDoubleAnimation1);
    sb.Children.Add(myDoubleAnimation2);

    Storyboard.SetTarget(myDoubleAnimation1, myRectangle);
    Storyboard.SetTarget(myDoubleAnimation2, myRectangle);

    // Set the attached properties of Canvas.Left and Canvas.Top
    // to be the target properties of the two respective DoubleAnimations.
    Storyboard.SetTargetProperty(
             myDoubleAnimation1, new PropertyPath("(Canvas.Left)"));
    Storyboard.SetTargetProperty(
             myDoubleAnimation2, new PropertyPath("(Canvas.Top)"));

    myDoubleAnimation1.To = 200;
    myDoubleAnimation2.To = 200;

    // Make the Storyboard a resource.
    LayoutRoot.Resources.Add("unique_id", sb);

    // Begin the animation.
    sb.Begin();
    // Sample code to localize the ApplicationBar
    //BuildLocalizedApplicationBar();
}

但是，当我运行模拟器时，我得到一个不会移动的红色方块。可能是什么问题呢？

谢谢！