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c#wpflistboxitem

WPF ListBoxItem: Overwrite SystemColors by Style has no effect

I'd like to overwrite SystemColors of a ListBoxItem. My target is to change the background of a selected but not focused item. By default it is grayed out when focus is lost eg. by showing the context menu. I do not want fancy complex style-sugar-code, just something very simple. I found several threads on the net about overwrite the SystemColors but non of them worked.

The following copy-paste-code does not work and the brushes will be ignored and it has no effect.

<Window x:Class="WpfAppListBoxItemBrushes.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:sys="clr-namespace:System;assembly=mscorlib"
    mc:Ignorable="d"
    Title="MainWindow" Height="200" Width="400">
<ListBox>
    <ListBox.ItemsSource>
        <x:Array Type="sys:String">
            <sys:String>1st item</sys:String>
            <sys:String>2nd item</sys:String>
        </x:Array>
    </ListBox.ItemsSource>
    
    <ListBox.ContextMenu>
        <ContextMenu>
            <MenuItem Header="Test"/>
        </ContextMenu>
    </ListBox.ContextMenu>

    <ListBox.Resources>
        <Style TargetType="ListBoxItem">
            <Style.Resources>
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveBorderBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveBorderColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionTextBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ActiveCaptionTextColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkDarkBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlDarkDarkColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveBorderBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveBorderColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionTextBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveCaptionTextColorKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="Red" />
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightTextBrushKey}" Color="Red" />
            </Style.Resources>
        </Style>
    </ListBox.Resources>
</ListBox>

The style definition has no effect on the ListBoxItem at all. What's wrong with this code?

enter image description here

Solution

  • I am afraid this is not possible because the brushes are hardcoded in the default template of the ListBoxItem.

    So you will have to copy the entire template into your XAML markup and then modify it as per your requirements.

    You cannot "override" the brushes without using a custom template.