列表框项目的 DataTemplate 中 IsSelected 的 WPF 触发器 [英] WPF Trigger for IsSelected in a DataTemplate for ListBox items
问题描述
我有一个列表框,我有以下 ItemTemplate:
I have a listbox, and I have the following ItemTemplate for it:
<DataTemplate x:Key="ScenarioItemTemplate">
<Border Margin="5,0,5,0"
Background="#FF3C3B3B"
BorderBrush="#FF797878"
BorderThickness="2"
CornerRadius="5">
<DockPanel>
<DockPanel DockPanel.Dock="Top"
Margin="0,2,0,0">
<Button HorizontalAlignment="Left"
DockPanel.Dock="Left"
FontWeight="Heavy"
Foreground="White" />
<Label Content="{Binding Path=Name}"
DockPanel.Dock="Left"
FontWeight="Heavy"
Foreground="white" />
<Label HorizontalAlignment="Right"
Background="#FF3C3B3B"
Content="X"
DockPanel.Dock="Left"
FontWeight="Heavy"
Foreground="White" />
</DockPanel>
<ContentControl Name="designerContent"
Visibility="Collapsed"
MinHeight="100"
Margin="2,0,2,2"
Content="{Binding Path=DesignerInstance}"
Background="#FF999898">
</ContentControl>
</DockPanel>
</Border>
</DataTemplate>
如您所见,ContentControl 的可见性设置为折叠.
As you can see the ContentControl has Visibility set to collapsed.
我需要定义一个触发器来将 Visibility 设置为Visible"
I need to define a trigger that causes the Visibility to be set to "Visible"
当 ListItem 被选中时,但我无法弄清楚.
when the ListItem is selected, but I can't figure it out.
有什么想法吗?
更新:当然我可以简单地复制 DataTemplate 并添加触发器到有问题的 ListBox 以使用其中一个,但我想防止重复此代码.
UPDATE: Of course I could simply duplicate the DataTemplate and add triggers to the ListBox in question to use either one or the other, but I want to prevent duplicating this code.
推荐答案
您可以设置 ContentControl 的样式,以便在其容器(ListBoxItem)被选中时触发触发器:
You can style your ContentControl such that a trigger fires when its container (the ListBoxItem) becomes selected:
<ContentControl
x:Name="designerContent"
MinHeight="100"
Margin="2,0,2,2"
Content="{Binding Path=DesignerInstance}"
Background="#FF999898">
<ContentControl.Style>
<Style TargetType="{x:Type ContentControl}">
<Setter Property="Visibility" Value="Collapsed"/>
<Style.Triggers>
<DataTrigger
Binding="{Binding
RelativeSource={RelativeSource
Mode=FindAncestor,
AncestorType={x:Type ListBoxItem}},
Path=IsSelected}"
Value="True">
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ContentControl.Style>
</ContentControl>
或者,我认为您可以将触发器添加到模板本身并按名称引用控件.我不太了解这种技术,无法从记忆中键入它并假设它会起作用,但它是这样的:
Alternatively, I think you can add the trigger to the template itself and reference the control by name. I don't know this technique well enough to type it from memory and assume it'll work, but it's something like this:
<DataTemplate x:Key="ScenarioItemTemplate">
<DataTemplate.Triggers>
<DataTrigger
Binding="{Binding
RelativeSource={RelativeSource
Mode=FindAncestor,
AncestorType={x:Type ListBoxItem}},
Path=IsSelected}"
Value="True">
<Setter
TargetName="designerContent"
Property="Visibility"
Value="Visible"/>
</DataTrigger>
</DataTemplate.Triggers>
...
</DataTemplate>
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