change properties inside datatemplate of listboxItem if selected - wpf

Question

I have the following style:
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock x:Name="Text" Text="{Binding Name}" Margin="0, 5" FontSize="16"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
I want to change the foreground color of "Text" if the "ListBoxItem" is selected. I know from here: Change WPF DataTemplate for ListBox item if selected how to change the DataTemplate. but since I just want to change colors, this solution makes unnecessary duplication in codd - It would be a greater problem if my DataTemplate would be very complex and long.
How do I achieve change of a single property of an object inside the DataTemplate?

Answer 1

If you actually want the same item template always (whether the item is selected or not), but you want a different foreground color when the item is selected, that's easy. Don't set the ContentTemplate in a trigger, because ContentTemplate doesn't change. Just set the foreground color with a trigger. If you don't mess with the foreground color in the template, it will inherit whatever the ListBoxItem has for that property.
<Style TargetType="ListBoxItem">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock
x:Name="Text"
Text="{Binding Name}"
Margin="0, 5"
FontSize="16"
/>
</DataTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Foreground" Value="Red" />
</Trigger>
</Style.Triggers>
</Style>
A more elaborate version of the same style:
<Style TargetType="ListBoxItem">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Ellipse
Height="12"
Width="12"
VerticalAlignment="Center"
x:Name="Ellipse"
Fill="Yellow"
Stroke="DeepSkyBlue"
StrokeThickness="1"
/>
<TextBlock
x:Name="Text"
Text="{Binding Name}"
Margin="5,5,0,5"
FontSize="16"
/>
</StackPanel>
<DataTemplate.Triggers>
<DataTrigger
Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=ListBoxItem}}"
Value="True"
>
<Setter
TargetName="Ellipse"
Property="Stroke"
Value="Orange"
/>
<Setter
TargetName="Ellipse"
Property="StrokeThickness"
Value="3"
/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Foreground" Value="Red" />
</Trigger>
</Style.Triggers>
</Style>