Question

I have a data bound tab control:

<TabControl ItemsSource="{Binding Products}" Name="ProductsTabControl">
  <TabControl.ItemTemplate>
    <DataTemplate>
      <TextBlock Text="{Binding Name}"/>
    </DataTemplate>
  </TabControl.ItemTemplate>
</TabControl>

This control is showing one tab per product, however I would like to make the tabs of discontinued products semi-transparent (i.e. set their opacity to 0.2). How can I change the opacity property of the tabitem when the item is being auto generated. I know I could use a style to change them all, but I only want to change those which are discontinued.

Answer 1

In ItemsContainerStyle for TabControl, create a DataTrigger where you bind to your property (e.g IsDiscontinued) and set the Opacity from there

<TabControl ItemsSource="{Binding Products}" Name="ProductsTabControl">
    <TabControl.ItemContainerStyle>
        <Style TargetType="TabItem">
            <Style.Triggers>
                <DataTrigger Binding="{Binding IsDiscontinued}" Value="True">
                    <Setter Property="Opacity" Value="0.2"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TabControl.ItemContainerStyle>
    <TabControl.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Name}"/>
        </DataTemplate>
    </TabControl.ItemTemplate>
</TabControl>

Update

If you want to make the Content of the discontinued tabs semi-transparent you can do the same thing, but in the DataTemplate

<TabControl ItemsSource="{Binding Products}" Name="ProductsTabControl">
    <TabControl.Resources>
        <DataTemplate DataType="{x:Type local:Product}">
            <Border Name="bg" BorderBrush="Black" BorderThickness="1">
                <TextBlock Text="{Binding Name}"/>
            </Border>
            <DataTemplate.Triggers>
                <DataTrigger Binding="{Binding IsDiscontinued}" Value="True">
                    <Setter TargetName="bg" Property="Opacity" Value="0.2"/>
                </DataTrigger>
            </DataTemplate.Triggers>
        </DataTemplate>
    </TabControl.Resources>
    <!--...-->
</TabControl>