Silverlight for Windows Mobile中的Storyboard.GetTarget

Question

我有一个WP7应用程序的问题。我正在尝试编写WPF应用程序窗体WPF示例代码。

private void storyboard_Completed(object sender, EventArgs e) 
    { 
     ClockGroup clockGroup = (ClockGroup)sender; 

     // Get the first animation in the storyboard, and use it to find the 
     // bomb that's being animated. 
     DoubleAnimation completedAnimation = (DoubleAnimation)clockGroup.Children[0].Timeline; 
     Bomb completedBomb = (Bomb)Storyboard.GetTarget(completedAnimation); 

似乎没有ClockGroup类和故事板没有了getTarget方法（这是一个有点奇怪的Cuz有SetTarget法）。是否有黑客获得他相同的功能？

Answer 1

我对WPF知之甚少，但在Silverlight或WP7中，Storyboard的孩子属于TimeLine类型。另外一个StoryBoard本身会有一个你将要绑定的Completed事件。所以至少第一部分的代码看起来像： -

private void storyboard_Completed(object sender, EventArgs e) 
{ 
    Storyboard sb = (Storyboard)sender; 

    DoubleAnimation completedAnimation = (DoubleAnimation)sb.Children[0]; 

现在的棘手的一点。

其实在Silverlight代码中使用Storyboard.SetTarget其实很不寻常。我猜游戏代码更有可能在代码中生成元素和动画，因此更有可能使用SetTarget。如果这是你想要做的，那么你将需要建立你自己的既有Get和Set属性的附属属性，在这个属性上调用回调函数Storyboard.SetTarget。

下面是代码： -

public static class StoryboardServices 
{ 
    public static DependencyObject GetTarget(Timeline timeline) 
    { 
     if (timeline == null) 
      throw new ArgumentNullException("timeline"); 

     return timeline.GetValue(TargetProperty) as DependencyObject; 
    } 

    public static void SetTarget(Timeline timeline, DependencyObject value) 
    { 
     if (timeline == null) 
      throw new ArgumentNullException("timeline"); 

     timeline.SetValue(TargetProperty, value); 
    } 

    public static readonly DependencyProperty TargetProperty = 
      DependencyProperty.RegisterAttached(
        "Target", 
        typeof(DependencyObject), 
        typeof(Timeline), 
        new PropertyMetadata(null, OnTargetPropertyChanged)); 

    private static void OnTargetPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) 
    { 
     Storyboard.SetTarget(d as Timeline, e.NewValue as DependencyObject); 
    } 
} 

现在SetTarget代码将变为： -

StoryboardServices.SetTarget(completedAnimation, bomb); 

然后你完成的事件可以检索的目标： -

Bomb completedBomb = (Bomb)StoryboardServices.GetTarget(completedAnimation);