如何在WPF中实现鼠标离开触发器？

Question

如何在WPF中实现鼠标离开触发器？

我试过这种方式，但它不起作用：

<EventTrigger RoutedEvent="MouseEnter">
      <EventTrigger.Actions>
        <BeginStoryboard>
          <Storyboard>
            <DoubleAnimation
              Duration="0:0:0.2"
              Storyboard.TargetProperty="MaxHeight"
              To="90"  />
          </Storyboard>
        </BeginStoryboard>
      </EventTrigger.Actions>
    </EventTrigger>
    <EventTrigger RoutedEvent="MouseLeave">
      <EventTrigger.Actions>
        <BeginStoryboard>
          <Storyboard>
            <DoubleAnimation
              Duration="0:0:1"
              Storyboard.TargetProperty="MaxHeight"  />
          </Storyboard>
        </BeginStoryboard>
      </EventTrigger.Actions>
    </EventTrigger>

Answer 1

我复制了你的代码，一切正常，

我怀疑你没有设置MaxHeight的初始值和动画如果没有动画，因为它的值为DependencyProperty.UnsetValue

以下是我在下面测试过的代码，有帮助

<Rectangle Width="100" Height="100" Fill="Blue" MaxHeight="100">
    <Rectangle.Triggers>
        <EventTrigger RoutedEvent="MouseEnter">
            <EventTrigger.Actions>
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetProperty="MaxHeight" To="90" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger.Actions>
        </EventTrigger>
        <EventTrigger RoutedEvent="MouseLeave">
            <EventTrigger.Actions>
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation Duration="0:0:1" Storyboard.TargetProperty="MaxHeight"  />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger.Actions>
        </EventTrigger>
    </Rectangle.Triggers>
</Rectangle>