yck1509-ConfuserEx/ConfuserEx/CompComboBox.xaml

<UserControl x:Class="ConfuserEx.CompComboBox"
             x:Name="Root"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:core="clr-namespace:Confuser.Core;assembly=Confuser.Core">
    <ComboBox ItemsSource="{Binding Components, ElementName=Root}"
              SelectedItem="{Binding SelectedComponent, ElementName=Root}"
              DisplayMemberPath="Id" FontFamily="Consolas"
              ScrollViewer.CanContentScroll="False">
        <ComboBox.ItemContainerStyle>
            <Style TargetType="{x:Type ComboBoxItem}">
                <Setter Property="OverridesDefaultStyle" Value="True" />
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                            <Border Width="350" BorderBrush="{StaticResource Foreground}"
                                    Background="{TemplateBinding Background}" BorderThickness="1" Margin="5">
                                <Grid Background="Transparent">
                                    <Grid.RowDefinitions>
                                        <RowDefinition />
                                        <RowDefinition />
                                    </Grid.RowDefinitions>
                                    <Label Grid.Row="0" Content="{Binding Name}" HorizontalAlignment="Left" />
                                    <Label Grid.Row="0" Content="{Binding Id}" HorizontalAlignment="Right" />
                                    <Label Grid.Row="1">
                                        <TextBlock Text="{Binding Description}" TextTrimming="WordEllipsis"
                                                   FontSize="10" Foreground="Gray" />
                                    </Label>
                                </Grid>
                            </Border>
                            <ControlTemplate.Triggers>
                                <Trigger Property="IsMouseOver" Value="True">
                                    <Setter Property="Background" Value="{StaticResource HighlightBackground}" />
                                    <Setter Property="Foreground" Value="{StaticResource SelectedForeground}" />
                                </Trigger>
                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </ComboBox.ItemContainerStyle>
    </ComboBox>
</UserControl>