wpf - 绑定(bind)到 DoubleAnimation.To

Question

我希望将 DoubleAnimation.To 绑定(bind)到依赖属性，并在该属性更改时触发动画。我可以让基本动画正常工作，但无法弄清楚如何在属性更改时触发它。

该示例显示我尝试为 Rectangle 的 Canvas.Left 属性设置动画。请注意，我已将 DoubleAnimation.To 绑定(bind)到 Position。我希望动画在位置更改时运行并移动我的矩形。有人可以帮我找出正确的触发器吗？

<Viewbox>
<Canvas Height="200" Width="200">
    <Rectangle Name="MyRectangle" Canvas.Left="50" Canvas.Top="50" Width="100" Height="100" Fill="Blue">
        <Rectangle.Triggers>
            <EventTrigger RoutedEvent="Rectangle.Loaded">
                <BeginStoryboard>
                    <Storyboard Name="MyStoryboard">
                        <DoubleAnimation Storyboard.TargetName="MyRectangle" 
                                            Storyboard.TargetProperty="(Canvas.Left)"
                                            To="{Binding Position}" Duration="0:0:5" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Rectangle.Triggers>
    </Rectangle>
</Canvas>

Answer 1

答案是使用 EventTrigger 并将其 RoutedEvent 属性设置为 Binding.TargetUpdated。另外，您必须将 NotifyOnTargetUpdated=True 添加到您的绑定(bind)中(在我的例子中为“位置”)。

        <Viewbox>
        <Canvas Height="200" Width="200">
            <Rectangle Name="MyRectangle" Canvas.Left="50" Canvas.Top="50" Width="100" Height="100" Fill="Blue">
                <Rectangle.Triggers>
                    <EventTrigger RoutedEvent="Binding.TargetUpdated">
                        <BeginStoryboard>
                            <Storyboard Name="MyStoryboard">
                                <DoubleAnimation Storyboard.TargetName="MyRectangle" 
                                                    Storyboard.TargetProperty="(Canvas.Left)"
                                                    To="{Binding Position, NotifyOnTargetUpdated=True}" Duration="0:0:5" />
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger>
                </Rectangle.Triggers>
            </Rectangle>
        </Canvas>
    </Viewbox>