WPF

<Style x:Key="ToolTipDataPointStyle" TargetType="chartingToolkit:LineDataPoint">
            <Setter Property="Background" Value="Green"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="chartingToolkit:LineDataPoint">
                        <Grid x:Name="Root" Opacity="1">
                            <ToolTipService.ToolTip>
                                <StackPanel Margin="2,2,2,2">
                                    <ContentControl Content="{Binding HoleSize}"  ContentStringFormat="Hole Size: {0}" />
                                    <ContentControl Content="{Binding PulseWidth}"  ContentStringFormat="Pulse Width: {0}"/>
                                    <!--<ContentControl Content="{Binding Path.[0]}"  ContentStringFormat="Data = {0}"/>-->
                                </StackPanel>
                            </ToolTipService.ToolTip>
                            <Ellipse StrokeThickness="{TemplateBinding BorderThickness}" Stroke="{TemplateBinding BorderBrush}" Fill="{TemplateBinding Background}"/>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Luna" 
    x:Class="Guardian.PAS.PASFramework.UI.WPF.PASComboBox"
    xmlns:local="clr-namespace:Guardian.PAS.PASFramework.UI.WPF"
    Height="26" Width="100" VerticalAlignment="Center" >
    <UserControl.Resources>
        <Style x:Key="comboBoxStyle" TargetType="{x:Type local:PASCustomComboBox}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type local:PASCustomComboBox}">
                        <ControlTemplate.Triggers>
                            <Trigger Property="local:PASCustomComboBox.IsEnabled" Value="false">
                                <Setter Property="Background" Value="Red"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </UserControl.Resources>
    <Canvas Name="canvas" Height="23" Width="Auto" VerticalAlignment="Center">
        <Label Height="23" Name="lblCaption" Width="20" VerticalAlignment="Center">aaa</Label>
        <local:PASCustomComboBox Height="23" x:Name="cmbComboBoxControl" VerticalAlignment="Center"  Width="50" 
                  IsEditable="True"  Style="{StaticResource comboBoxStyle}">
            </local:PASCustomComboBox>
        <Button Height="23" Name="btnSearch" Width="25" Click="btnSearch_Click" Visibility="Collapsed" 
                VerticalAlignment="Center">...</Button>
        <Label Height="23" Name="lblDescription" VerticalAlignment="Center" Width="20" Foreground="Blue">
            
        </Label>
        
    </Canvas>
</UserControl>

public class PASCustomComboBox : ComboBox
{
    protected override void OnPreviewKeyDown(KeyEventArgs e)
    {
        if (e.Key == Key.Down || e.Key == Key.Up)
        {
            e.Handled = true;
            return;
        }

        base.OnPreviewKeyDown(e);
    }

}