WPF XAML 网格可见性触发器
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/18881851/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
WPF XAML Grid Visibility Trigger
提问by Mikkeee
I have a status message located on the first row of my grid and I want it to slide in and out when the visibility changes.
The first visibility trigger works great and slides the first grid row open quickly. As soon as I add the 'Collapsed' trigger, nothing works at all. How do I reverse the animation to slide closed when the visibility is set to collapsed?
我在网格的第一行有一条状态消息，我希望它在可见性改变时滑入和滑出。
第一个可见性触发器效果很好，可以快速打开第一个网格行。一旦我添加了“折叠”触发器，就没有任何效果。当可见性设置为折叠时，如何反转动画以滑动关闭？
<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>
回答by Adi Lester
You should remove the Visibilitybinding in your grid and use a DataTriggerthat binds to the StatusMessageVisibilityproperty. If you bind the grid's visibility then once it's collapsed it's collapsed and you won't be able to see the animation.
您应该删除Visibility网格中的绑定并使用DataTrigger绑定到StatusMessageVisibility属性的 。如果您绑定了网格的可见性，那么一旦它折叠起来，它就会折叠起来，您将无法看到动画。
Also, instead of having two data triggers with EnterActions, use a single data trigger that also has an ExitActionfor the collapsed state:
此外，不要使用带有 的两个数据触发器，而是EnterActions使用一个也具有ExitAction用于折叠状态的数据触发器：
<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>
