WPF XAML网格可见性触发器

Question

我有一个位于网格第一行的状态消息,我希望它在可见性发生变化时滑入和滑出.
第一个可见性触发器运行良好,并快速打开第一个网格行.一旦我添加'Collapsed'触发器,一切都无效.当可见性设置为折叠时,如何将动画反转为滑动关闭？

<Grid Grid.Row="0" Height="55" Visibility="{Binding StatusMessageVisibility, Mode=TwoWay}">
    <Grid.Style>
        <Style TargetType="Grid">
            <Style.Triggers>
                <Trigger Property="Visibility" Value="Visible">
                    <Trigger.EnterActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="Height" From="0" To="55" Duration="0:0:.1" />
                            </Storyboard>
                        </BeginStoryboard>
                    </Trigger.EnterActions>
                </Trigger>
                <Trigger Property="Visibility" Value="Collapsed">
                    <Trigger.EnterActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="Height" From="55" To="0" Duration="0:0:.1" />
                            </Storyboard>
                        </BeginStoryboard>
                    </Trigger.EnterActions>
                </Trigger>                        
            </Style.Triggers>
        </Style>
    </Grid.Style>
    <TextBlock Text="Hi There" />
</Grid>

Answer 1

您应该删除Visibility网格中的绑定并使用DataTrigger绑定到StatusMessageVisibility属性的绑定.如果你绑定了网格的可见性,那么一旦它被折叠,它就会折叠,你将无法看到动画.

此外,不使用两个数据触发器,而是EnterActions使用单个数据触发器,该触发器也具有ExitAction折叠状态:

<Grid Grid.Row="0" Height="55">
    <Grid.Style>
        <Style TargetType="Grid">
            <Style.Triggers>
                <DataTrigger Binding="{Binding StatusMessageVisibility}" Value="Visible">
                    <DataTrigger.EnterActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="Height" From="0" To="55" Duration="0:0:.1" />
                            </Storyboard>
                        </BeginStoryboard>
                    </DataTrigger.EnterActions>
                    <DataTrigger.ExitActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="Height" From="55" To="0" Duration="0:0:0.1" />
                            </Storyboard>
                        </BeginStoryboard>
                    </DataTrigger.ExitActions>
                </DataTrigger>               
            </Style.Triggers>
        </Style>
    </Grid.Style>
    <TextBlock Text="Hi There" />
</Grid>