WPF中用C#通过Storyboard实现RectangleGeometry动画：PropertyPath路径疑问

要为RectangleGeometry的Rect属性创建Storyboard动画，PropertyPath的写法由你指定的目标对象决定：

• 若target是直接获取的RectangleGeometry实例（比如从Image的Clip属性中取出），路径写"Rect"
• 若target是Image控件（即XAML中的Item），路径写成"Clip.Rect"

修改后的代码示例 #

场景1：目标为RectangleGeometry实例

// 从Image的Clip中获取RectangleGeometry
var clipGeometry = Item.Clip as RectangleGeometry;

RectAnimation rectAnimation = new RectAnimation
{
    Duration = TimeSpan.FromMilliseconds(toMills - fromMills),
    FillBehavior = FillBehavior.HoldEnd,
    From = new Rect(xFrom, yFrom, wFrom, hFrom),
    To = new Rect(xTo, yTo, wTo, hTo)
};

// 设置动画目标为RectangleGeometry
rectAnimation.SetValue(Storyboard.TargetProperty, clipGeometry);
// 指定属性路径为"Rect"
rectAnimation.SetValue(Storyboard.TargetPropertyProperty, new PropertyPath("Rect"));

storyboard.Children.Add(rectAnimation);

场景2：目标为Image控件

RectAnimation rectAnimation = new RectAnimation
{
    Duration = TimeSpan.FromMilliseconds(toMills - fromMills),
    FillBehavior = FillBehavior.HoldEnd,
    From = new Rect(xFrom, yFrom, wFrom, hFrom),
    To = new Rect(xTo, yTo, wTo, hTo)
};

// 设置动画目标为Image控件
rectAnimation.SetValue(Storyboard.TargetProperty, Item);
// 通过属性路径访问Clip下的Rect属性
rectAnimation.SetValue(Storyboard.TargetPropertyProperty, new PropertyPath("Clip.Rect"));

storyboard.Children.Add(rectAnimation);

额外扩展：动画ScaleTransform的写法 #

如果需要对XAML中RectangleGeometry下的ScaleTransform做动画（比如修改ScaleX），对应的PropertyPath：

• 若目标是ScaleTransform实例："ScaleX"
• 若目标是RectangleGeometry实例："Transform.Children[0].ScaleX"（Transform是TransformGroup，第一个子元素为ScaleTransform）
• 若目标是Image控件："Clip.Transform.Children[0].ScaleX"

内容的提问来源于stack exchange，提问作者Andrea