绑定到DoubleAnimation.To

Question

我希望将DoubleAnimation.To绑定到依赖属性，并在该属性更改时触发动画。我可以让基本的动画工作，但不知道如何在属性改变时触发它。

这个例子展示了我试图让Rectangle的Canvas.Left属性动画化。请注意，我已经将DoubleAnimation.To绑定到了位置。我想让动画在位置改变时运行并移动我的矩形。有人能帮我找出正确的引爆器吗？

<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。此外，您还必须将NotifyOnTargetUpdated=True添加到绑定中(在我的示例中，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>