WPF Trigger for IsSelected in a DataTemplate for ListBox items

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>

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>

@Matt, Thank you!!!

Just had to add a trigger for IsSelected == false as well,and now it works like a charm!

<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>        <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ListBoxItem}},Path=IsSelected}" Value="False">            <Setter Property="Visibility" Value="Collapsed"/>        </DataTrigger>    </Style.Triggers></Style>