以编程方式在 WPF ControlTemplate 中创建 Storyboard

我有一个加载的 WPF 应用程序Pages在模板化的NavigationWindow。我想在加载新页面时实现幻灯片过渡，并且由于可以调整窗口大小，因此据我所知，需要以编程方式确定转换的目标值。

我在中尝试了以下操作NavigationWindow代码隐藏，但触发时没有任何效果。这PageContentContainerTransform根据调试器的确定，也被正确定位。

public void DoTransition()
{
    double targetX = this.ActualWidth;

    this.TransitionStoryboard.Stop();
    this.TransitionStoryboard.Children.Clear();
    IEasingFunction easing = new QuadraticEase() { EasingMode = EasingMode.EaseOut };
    DoubleAnimation translateXAnim = new DoubleAnimation() {
        To = targetX,
        Duration = TimeSpan.FromMilliseconds(250),
        EasingFunction = easing,
    };

    DependencyObject d = this.Template.FindName("pageContentContainerTransform", this) as DependencyObject;
    Storyboard.SetTarget(translateXAnim, d);

    Storyboard.SetTargetProperty(translateXAnim, new PropertyPath(TranslateTransform.XProperty));
    this.TransitionStoryboard.Children.Add(translateXAnim);
    this.TransitionStoryboard.Begin();
}

The Template is a ControlTemplate包含以下 XAML 位，

...
<ContentPresenter 
    Grid.Row="1"
    x:Name="pageContentContainer"
    MaxHeight="{StaticResource ContentWindowMaxHeight}"
    MaxWidth="{StaticResource ContentWindowMaxWidth}"
    RenderTransformOrigin="0.5,0.5">
    <ContentPresenter.RenderTransform>
        <TranslateTransform x:Name="pageContentContainerTransform" X="0" Y="0" />
    </ContentPresenter.RenderTransform>
</ContentPresenter>
...

为什么没有效果呢？

Update

如果您直接对元素进行动画处理而不将其包装在 a 中，则动画会起作用Storyboard目的。例如。

public void DoTransition()
{
    double targetX = this.ActualWidth;

    this.TransitionStoryboard.Stop();
    this.TransitionStoryboard.Children.Clear();
    IEasingFunction easing = new QuadraticEase() { EasingMode = EasingMode.EaseOut };
    DoubleAnimation translateXAnim = new DoubleAnimation() {
        To = targetX,
        Duration = TimeSpan.FromMilliseconds(250),
        EasingFunction = easing,
    };

    TranslateTransform t = this.Template.FindName("pageContentContainerTransform", this) as TranslateTransform;
    t.BeginAnimation(TranslateTransform.XProperty, translateXAnim);

}

但是，您可能会错过 Storyboard 对象提供的一些不错的动画控制元素，例如管理动画（停止、开始等）。似乎有可能的论点.Begin()在与模板中使用相关的故事板对象上，但是使用.Begin(this, this.Template)也没有做任何事情。

最终，多种因素的综合作用使其发挥作用。首先，使用Storyboard.SetTargetName而不是Storyboard.SetTarget。其次将模板上下文传递给Begin()方法。例如。

public void DoTransition()
{
    double targetX = this.ActualWidth;

    this.TransitionStoryboard.Stop();
    this.TransitionStoryboard.Children.Clear();
    IEasingFunction easing = new QuadraticEase() { EasingMode = EasingMode.EaseOut };
    DoubleAnimation translateXAnim = new DoubleAnimation() {
        To = targetX,
        Duration = TimeSpan.FromMilliseconds(250),
        EasingFunction = easing,
    };

    // 1. Refer to the element by Name
    Storyboard.SetTargetName(translateXAnim, "pageContentContainerTransform");
    Storyboard.SetTargetProperty(translateXAnim, new PropertyPath(TranslateTransform.XProperty));
    this.TransitionStoryboard.Children.Add(translateXAnim);
    // 2. Pass in the template context here
    this.TransitionStoryboard.Begin(this, this.Template);    
}

我不清楚为什么SetTargetProperty当你考虑到这一点时不起作用FindName正确识别了模板中的元素，但无论如何上述方法都有效。