为边框控件的宽度设置动画

Question

我正在尝试在 Windows 8 Metro 应用程序中为边框控件的宽度设置动画。我已经成功地为边界上的其他属性设置了动画，例如不透明度：

private void Item_Tapped(object sender, RoutedEventArgs e)
{
    var border = sender as Border;

    var animation = new DoubleAnimation();
    animation.To = 0.0;
    animation.Duration = new Duration(TimeSpan.FromSeconds(1));

    var storyboard = new Storyboard();
    storyboard.Children.Add(animation);

    Storyboard.SetTarget(animation, border);
    Storyboard.SetTargetProperty(animation, "Opacity");

    storyboard.Begin();
}

但是当我尝试为控件的宽度设置动画时：

private void Item_Tapped(object sender, RoutedEventArgs e)
{
    var border = sender as Border;

    var animation = new DoubleAnimation();
    animation.To = 600.0;
    animation.Duration = new Duration(TimeSpan.FromSeconds(1));

    var storyboard = new Storyboard();
    storyboard.Children.Add(animation);

    Storyboard.SetTarget(animation, border);
    Storyboard.SetTargetProperty(animation, "Width");

    storyboard.Begin();
}

什么都没发生。

我可以在 WPF 中执行此操作，但不能在 Windows 8 中执行此操作。这是 Metro 的限制或错误，还是我做错了什么？

谢谢

Answer 1

我不确定你如何在WPF中工作。根据 http://msdn.microsoft.com/en-us/library/system.windows.media.animation.storyboard.targetProperty ，目标属性必须是依赖性属性。根据 http://msdn.microsoft.com/en-us/library/system.windows.controls.border ，宽度不是依赖属性。

Answer 2

我能够通过启用使其工作 EnableDependentAnimation

    public static async Task Width(FrameworkElement obj, double doubleValue, int milliseconds)
    {
        var animation= new DoubleAnimation
        {
            To = doubleValue,
            Duration = TimeSpan.FromMilliseconds(milliseconds),
            EnableDependentAnimation = true// <== here
        };

        Storyboard.SetTarget(animation, obj);
        Storyboard.SetTargetProperty(animation, "Width");

        var sb = new Storyboard();
        sb.Children.Add(animation);
        await sb.BeginAsync();
    }

享受！