Question

When a user clicks on an ListBoxItem, I want to it to be a bold larger font red background yellow

Everything works except the background. It seems that there is a standard (blue) background for the selected item. How do I override that and change the selected background yellow?

Here is the code:

<Window x:Class='AlternateListBox2.Window1'     xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'     xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'     Title='Window1' Height='300' Width='300'     xmlns:local='clr-namespace:AlternateListBox2'>     <Window.Resources>         <local:Countries x:Key='countries'/>         <Style TargetType='{x:Type ListBoxItem}'>             <Setter Property='Content' Value='{Binding Path=Name}'/>             <Setter Property='Margin' Value='2'/>             <Style.Triggers>                 <Trigger Property='IsSelected' Value='True'>                     <Setter Property='FontWeight' Value='Bold'/>                     <Setter Property='FontSize' Value='18'/>                     <Setter Property='Background' Value='Yellow'/>                     <Setter Property='Foreground' Value='Red'/>                 </Trigger>             </Style.Triggers>          </Style>     </Window.Resources>     <StackPanel>         <ListBox             ItemsSource='{Binding Source={StaticResource countries}}'             Width='100'             Margin='10'             HorizontalAlignment='Left'             />     </StackPanel> </Window> 

Answer 1

It can be done a lot simpler. The Background color for the selected ListBox items are taken from the SystemColors. So, what you need to do is override the SystemColors in the Resources of your ListBox:

<ListBox.Resources>     <!--Selected color when the ListBox is focused-->     <SolidColorBrush x:Key='{x:Static SystemColors.HighlightBrushKey}' Color='Yellow' />     <!--Selected color when the ListBox is not focused-->     <SolidColorBrush x:Key='{x:Static SystemColors.ControlBrushKey}' Color='Yellow' /> </ListBox.Resources>