为什么当我用故事板没有这些动画工作？ [英] Why don't these animations work when I'm using a storyboard?

问题描述

我创建的StackPanel 的一个简单的子类，我可以使用屏幕上走动动画 TranslateTransform 。它看起来是这样的：

I've created a simple subclass of StackPanel that I can move around on the screen using an animated TranslateTransform. It looks like this:

public class MovingStackPanel : StackPanel
{
    public void BeginMove(Point translatePosition)
    {
        RenderTransform = new TranslateTransform();
        Duration d = new Duration(new TimeSpan(0, 0, 0, 0, 400));
        DoubleAnimation x = new DoubleAnimation(translatePosition.X, d);
        DoubleAnimation y = new DoubleAnimation(translatePosition.Y, d);
        /*
        Storyboard.SetTarget(x, RenderTransform);
        Storyboard.SetTargetProperty(x, new PropertyPath("X"));

        Storyboard.SetTarget(y, RenderTransform);
        Storyboard.SetTargetProperty(y, new PropertyPath("Y"));

        Storyboard sb = new Storyboard();
        sb.Children.Add(x);
        sb.Children.Add(y);
        sb.Completed += sb_Completed;
        sb.Begin();
        */
        RenderTransform.BeginAnimation(TranslateTransform.XProperty, x);
        RenderTransform.BeginAnimation(TranslateTransform.YProperty, y);
    }

    void sb_Completed(object sender, EventArgs e)
    {
        Console.WriteLine("Completed.");
    }
} 

这是我的问题：如果我直接动画X和Y属性，如上面的code呢，它的工作原理。但是，如果我用注释掉code它上面，这实在是一个故事板在code可以想象的最简单的创造，没有任何反应。动画运行 - 至少，Completed事件引发获取 - 但在屏幕上没有什么变化。

And here is my problem: If I animate the X and Y properties directly, as the code above does, it works. But if I use the commented-out code above it, which is really the simplest creation of a Storyboard in code imaginable, nothing happens. The animation runs - at least, the Completed event gets raised - but nothing changes on the screen.

显然，我做错了什么，但我看不出它是什么。我见过code制作脚本的每一个例子看起来就像这样。有明显的一些关于动画和故事，我还不知道：这是什么？

Clearly I'm doing something wrong, but I can't see what it is. Every example of creating storyboards in code I've seen looks just like this. There's obviously something about animations and storyboards that I don't know yet: what is it?

推荐答案

事实证明，你不能使用在这种情况下属性路径语法，因为属性被动画不是 FrameworkElement的。至少，这就是我如何跨preT的显着扑朔迷离的例外，我得到的，当我作出这样的Anvaka建议改变：

As it turns out, you can't use property path syntax in this case, because the properties being animated aren't properties of a FrameworkElement. At least, that's how I interpret the remarkably bewildering exception that I get when I make the change that Anvaka suggested:

Cannot automatically create animation clone for frozen property values on     
'System.Windows.Media.TranslateTransform' objects. Only FrameworkElement and 
FrameworkContentElement (or derived) types are supported.

要制作动画的，现在看来，我必须使用名称范围，并使用 SetTargetName 来命名 TransformElement 。然后，只要我通过了 FrameworkElement的，我将名称设置范围到开始法，故事板就可以找对象和属性，并为它们制作动画，这一切的作品。最终的结果是这样的：

To animate those, it seems, I have to use a NameScope and use SetTargetName to name the TransformElement. Then, as long as I pass the FrameworkElement that I set the name scope on to the Begin method, the storyboard can find the object and the properties and animate them and it all works. The end result looks like this:

public void BeginMove(Point translatePosition)
{
    NameScope.SetNameScope(this, new NameScope());

    RenderTransform = new TranslateTransform();
    RegisterName("TranslateTransform", RenderTransform);

    Duration d = new Duration(new TimeSpan(0, 0, 0, 0, 400));
    DoubleAnimation x = new DoubleAnimation(translatePosition.X, d);
    DoubleAnimation y = new DoubleAnimation(translatePosition.Y, d);

    Storyboard.SetTargetName(x, "TranslateTransform");
    Storyboard.SetTargetProperty(x, new PropertyPath(TranslateTransform.XProperty));

    Storyboard.SetTargetName(y, "TranslateTransform");
    Storyboard.SetTargetProperty(y, new PropertyPath(TranslateTransform.YProperty));

    Storyboard sb = new Storyboard();
    sb.Children.Add(x);
    sb.Children.Add(y);
    sb.Completed += sb_Completed;

    // you must pass this to the Begin method, otherwise the timeline won't be
    // able to find the named objects it's animating because it doesn't know
    // what name scope to look in

    sb.Begin(this);

}

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