重写combobox模板,实现支持过滤的combobox

        private void ComboBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            TextBox textBox = e.OriginalSource as TextBox;

            ComboBox cbo = textBox.TemplatedParent as ComboBox;
            cbo.Items.Filter = null;
            cbo.Items.Filter += obj =>
            {
                bool result = false;
                var t = obj.GetType();
                var p = t.GetProperty(this.DisplayMemberPath);
                var text = (p.GetValue(obj) ?? "").ToString();
                if (text == null)
                {

                }
                else
                {
                    result = text.Contains(textBox.Text);
                }
                return result;
            };
        }

<ComboBox
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfApp2"
            xmlns:Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero2" x:Class="WpfApp2.FilterCombobox"
          TextBoxBase.TextChanged="ComboBox_TextChanged"
          KeyDown="combobox_KeyDown"
          StaysOpenOnEdit="True"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800" Style="{DynamicResource ComboBoxStyle1}">

    <ComboBox.Resources>
        <Style x:Key="FocusVisual">
            <Setter Property="Control.Template">
                <Setter.Value>
                    <ControlTemplate>
                        <Rectangle Margin="2" SnapsToDevicePixels="true" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" StrokeThickness="1" StrokeDashArray="1 2"/>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
        <LinearGradientBrush x:Key="ComboBox.Static.Background" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFF0F0F0" Offset="0.0"/>
            <GradientStop Color="#FFE5E5E5" Offset="1.0"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="ComboBox.Static.Border" Color="#FFACACAC"/>
        <SolidColorBrush x:Key="ComboBox.Static.Editable.Background" Color="#FFFFFFFF"/>
        <SolidColorBrush x:Key="ComboBox.Static.Editable.Border" Color="#FFABADB3"/>
        <SolidColorBrush x:Key="ComboBox.Static.Editable.Button.Background" Color="Transparent"/>
        <SolidColorBrush x:Key="ComboBox.Static.Editable.Button.Border" Color="Transparent"/>
        <SolidColorBrush x:Key="ComboBox.MouseOver.Glyph" Color="#FF000000"/>
        <LinearGradientBrush x:Key="ComboBox.MouseOver.Background" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFECF4FC" Offset="0.0"/>
            <GradientStop Color="#FFDCECFC" Offset="1.0"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="ComboBox.MouseOver.Border" Color="#FF7EB4EA"/>
        <SolidColorBrush x:Key="ComboBox.MouseOver.Editable.Background" Color="#FFFFFFFF"/>
        <SolidColorBrush x:Key="ComboBox.MouseOver.Editable.Border" Color="#FF7EB4EA"/>
        <LinearGradientBrush x:Key="ComboBox.MouseOver.Editable.Button.Background" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFEBF4FC" Offset="0.0"/>
            <GradientStop Color="#FFDCECFC" Offset="1.0"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="ComboBox.MouseOver.Editable.Button.Border" Color="#FF7EB4EA"/>
        <SolidColorBrush x:Key="ComboBox.Pressed.Glyph" Color="#FF000000"/>
        <LinearGradientBrush x:Key="ComboBox.Pressed.Background" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFDAECFC" Offset="0.0"/>
            <GradientStop Color="#FFC4E0FC" Offset="1.0"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="ComboBox.Pressed.Border" Color="#FF569DE5"/>
        <SolidColorBrush x:Key="ComboBox.Pressed.Editable.Background" Color="#FFFFFFFF"/>
        <SolidColorBrush x:Key="ComboBox.Pressed.Editable.Border" Color="#FF569DE5"/>
        <LinearGradientBrush x:Key="ComboBox.Pressed.Editable.Button.Background" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFDAEBFC" Offset="0.0"/>
            <GradientStop Color="#FFC4E0FC" Offset="1.0"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="ComboBox.Pressed.Editable.Button.Border" Color="#FF569DE5"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Glyph" Color="#FFBFBFBF"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Background" Color="#FFF0F0F0"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Border" Color="#FFD9D9D9"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Background" Color="#FFFFFFFF"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Border" Color="#FFBFBFBF"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Button.Background" Color="Transparent"/>
        <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Button.Border" Color="Transparent"/>
        <SolidColorBrush x:Key="ComboBox.Static.Glyph" Color="#FF606060"/>
        <Style x:Key="ComboBoxToggleButton" TargetType="{x:Type ToggleButton}">
            <Setter Property="OverridesDefaultStyle" Value="true"/>
            <Setter Property="IsTabStop" Value="false"/>
            <Setter Property="Focusable" Value="false"/>
            <Setter Property="ClickMode" Value="Press"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                        <Border x:Name="templateRoot" BorderBrush="{StaticResource ComboBox.Static.Border}" BorderThickness="{TemplateBinding BorderThickness}" Background="{StaticResource ComboBox.Static.Background}" SnapsToDevicePixels="true">
                            <Border x:Name="splitBorder" BorderBrush="Transparent" BorderThickness="1" HorizontalAlignment="Right" Margin="0" SnapsToDevicePixels="true" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}">
                                <Path x:Name="arrow" Data="F1 M 0,0 L 2.667,2.66665 L 5.3334,0 L 5.3334,-1.78168 L 2.6667,0.88501 L0,-1.78168 L0,0 Z" Fill="{StaticResource ComboBox.Static.Glyph}" HorizontalAlignment="Center" Margin="0" VerticalAlignment="Center"/>
                            </Border>
                        </Border>
                        <ControlTemplate.Triggers>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                    <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="false"/>
                                    <Condition Binding="{Binding IsPressed, RelativeSource={RelativeSource Self}}" Value="false"/>
                                    <Condition Binding="{Binding IsEnabled, RelativeSource={RelativeSource Self}}" Value="true"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Static.Editable.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Static.Editable.Border}"/>
                                <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.Static.Editable.Button.Background}"/>
                                <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.Static.Editable.Button.Border}"/>
                            </MultiDataTrigger>
                            <Trigger Property="IsMouseOver" Value="true">
                                <Setter Property="Fill" TargetName="arrow" Value="{StaticResource ComboBox.MouseOver.Glyph}"/>
                            </Trigger>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="true"/>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="false"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Border}"/>
                            </MultiDataTrigger>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="true"/>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Editable.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Editable.Border}"/>
                                <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.MouseOver.Editable.Button.Background}"/>
                                <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.MouseOver.Editable.Button.Border}"/>
                            </MultiDataTrigger>
                            <Trigger Property="IsPressed" Value="true">
                                <Setter Property="Fill" TargetName="arrow" Value="{StaticResource ComboBox.Pressed.Glyph}"/>
                            </Trigger>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsPressed, RelativeSource={RelativeSource Self}}" Value="true"/>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="false"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Border}"/>
                            </MultiDataTrigger>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsPressed, RelativeSource={RelativeSource Self}}" Value="true"/>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Editable.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Editable.Border}"/>
                                <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.Pressed.Editable.Button.Background}"/>
                                <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.Pressed.Editable.Button.Border}"/>
                            </MultiDataTrigger>
                            <Trigger Property="IsEnabled" Value="false">
                                <Setter Property="Fill" TargetName="arrow" Value="{StaticResource ComboBox.Disabled.Glyph}"/>
                            </Trigger>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsEnabled, RelativeSource={RelativeSource Self}}" Value="false"/>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="false"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Border}"/>
                            </MultiDataTrigger>
                            <MultiDataTrigger>
                                <MultiDataTrigger.Conditions>
                                    <Condition Binding="{Binding IsEnabled, RelativeSource={RelativeSource Self}}" Value="false"/>
                                    <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                </MultiDataTrigger.Conditions>
                                <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Editable.Background}"/>
                                <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Editable.Border}"/>
                                <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.Disabled.Editable.Button.Background}"/>
                                <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.Disabled.Editable.Button.Border}"/>
                            </MultiDataTrigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
        <ControlTemplate x:Key="ComboBoxTemplate" TargetType="{x:Type ComboBox}">
            <Grid x:Name="templateRoot" SnapsToDevicePixels="true">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition MinWidth="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" Width="0"/>
                </Grid.ColumnDefinitions>
                <Popup x:Name="PART_Popup" AllowsTransparency="true" Grid.ColumnSpan="2" IsOpen="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
                    <Themes:SystemDropShadowChrome x:Name="shadow" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=templateRoot}">
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="auto"/>
                                <RowDefinition />
                            </Grid.RowDefinitions>
                            <Border BorderBrush="Black" BorderThickness="1" Margin="0 1">
                                <DockPanel Background="White" Height="28">
                                    <Label VerticalContentAlignment="Center" DockPanel.Dock="Left" Content="过滤:" Height="28"/>
                                    <TextBox Name="tb3" Height="28" VerticalContentAlignment="Center" TextChanged="ComboBox_TextChanged"/>
                                </DockPanel>
                            </Border>
                            <Border Grid.Row="1" x:Name="dropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
                                <ScrollViewer x:Name="DropDownScrollViewer">
                                    <Grid x:Name="grid" RenderOptions.ClearTypeHint="Enabled">
                                        <Canvas x:Name="canvas" HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
                                            <Rectangle x:Name="opaqueRect" Fill="{Binding Background, ElementName=dropDownBorder}" Height="{Binding ActualHeight, ElementName=dropDownBorder}" Width="{Binding ActualWidth, ElementName=dropDownBorder}"/>
                                        </Canvas>
                                        <ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Contained" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                    </Grid>
                                </ScrollViewer>
                            </Border>
                        </Grid>
                    </Themes:SystemDropShadowChrome>
                </Popup>
                <ToggleButton x:Name="toggleButton" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxToggleButton}"/>
                <ContentPresenter x:Name="contentPresenter" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" Content="{TemplateBinding SelectionBoxItem}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" IsHitTestVisible="false" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
            </Grid>
            <ControlTemplate.Triggers>
                <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                    <Setter Property="Margin" TargetName="shadow" Value="0,0,5,5"/>
                    <Setter Property="Color" TargetName="shadow" Value="#71000000"/>
                </Trigger>
                <Trigger Property="HasItems" Value="false">
                    <Setter Property="Height" TargetName="dropDownBorder" Value="95"/>
                </Trigger>
                <MultiTrigger>
                    <MultiTrigger.Conditions>
                        <Condition Property="IsGrouping" Value="true"/>
                        <Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false"/>
                    </MultiTrigger.Conditions>
                    <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                </MultiTrigger>
                <Trigger Property="ScrollViewer.CanContentScroll" SourceName="DropDownScrollViewer" Value="false">
                    <Setter Property="Canvas.Top" TargetName="opaqueRect" Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}"/>
                    <Setter Property="Canvas.Left" TargetName="opaqueRect" Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}"/>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
        <SolidColorBrush x:Key="TextBox.Static.Background" Color="#FFFFFFFF"/>
        <Style x:Key="ComboBoxEditableTextBox" TargetType="{x:Type TextBox}">
            <Setter Property="OverridesDefaultStyle" Value="true"/>
            <Setter Property="AllowDrop" Value="true"/>
            <Setter Property="MinWidth" Value="0"/>
            <Setter Property="MinHeight" Value="0"/>
            <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
            <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
            <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type TextBox}">
                        <ScrollViewer x:Name="PART_ContentHost" Background="Transparent" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
        <ControlTemplate x:Key="ComboBoxEditableTemplate" TargetType="{x:Type ComboBox}">
            <Grid x:Name="templateRoot" SnapsToDevicePixels="true">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition MinWidth="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" Width="0"/>
                </Grid.ColumnDefinitions>
                <Popup x:Name="PART_Popup" AllowsTransparency="true" Grid.ColumnSpan="2" IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
                    <Themes:SystemDropShadowChrome x:Name="shadow" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=templateRoot}">
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="auto"/>
                                <RowDefinition />
                            </Grid.RowDefinitions>
                            <Border Grid.Row="1" x:Name="dropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
                                <ScrollViewer x:Name="DropDownScrollViewer">
                                    <Grid x:Name="grid" RenderOptions.ClearTypeHint="Enabled">
                                        <Canvas x:Name="canvas" HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
                                            <Rectangle x:Name="opaqueRect" Fill="{Binding Background, ElementName=dropDownBorder}" Height="{Binding ActualHeight, ElementName=dropDownBorder}" Width="{Binding ActualWidth, ElementName=dropDownBorder}"/>
                                        </Canvas>
                                        <ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Contained" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                    </Grid>
                                </ScrollViewer>
                            </Border>
                            <Border Grid.Row="0" BorderBrush="Black" BorderThickness="1">
                                <DockPanel >
                                    <Label VerticalAlignment="Center" Content="过滤" DockPanel.Dock="Left"/>
                                    <TextBox   TextChanged="ComboBox_TextChanged" />
                                </DockPanel>
                            </Border>
                        </Grid>
                    </Themes:SystemDropShadowChrome>
                </Popup>
                <ToggleButton x:Name="toggleButton" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxToggleButton}"/>
                <Border x:Name="border" Background="{StaticResource TextBox.Static.Background}" Margin="{TemplateBinding BorderThickness}">
                    <TextBox x:Name="PART_EditableTextBox" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsReadOnly="{Binding IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}" Margin="{TemplateBinding Padding}" Style="{StaticResource ComboBoxEditableTextBox}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Border>
            </Grid>
            <ControlTemplate.Triggers>
                <Trigger Property="IsEnabled" Value="false">
                    <Setter Property="Opacity" TargetName="border" Value="0.56"/>
                </Trigger>
                <Trigger Property="IsKeyboardFocusWithin" Value="true">
                    <Setter Property="Foreground" Value="Black"/>
                </Trigger>
                <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                    <Setter Property="Margin" TargetName="shadow" Value="0,0,5,5"/>
                    <Setter Property="Color" TargetName="shadow" Value="#71000000"/>
                </Trigger>
                <Trigger Property="HasItems" Value="false">
                    <Setter Property="Height" TargetName="dropDownBorder" Value="95"/>
                </Trigger>
                <MultiTrigger>
                    <MultiTrigger.Conditions>
                        <Condition Property="IsGrouping" Value="true"/>
                        <Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false"/>
                    </MultiTrigger.Conditions>
                    <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                </MultiTrigger>
                <Trigger Property="ScrollViewer.CanContentScroll" SourceName="DropDownScrollViewer" Value="false">
                    <Setter Property="Canvas.Top" TargetName="opaqueRect" Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}"/>
                    <Setter Property="Canvas.Left" TargetName="opaqueRect" Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}"/>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
        <Style x:Key="ComboBoxStyle1" TargetType="{x:Type ComboBox}">
            <Setter Property="FocusVisualStyle" Value="{StaticResource FocusVisual}"/>
            <Setter Property="Background" Value="{StaticResource ComboBox.Static.Background}"/>
            <Setter Property="BorderBrush" Value="{StaticResource ComboBox.Static.Border}"/>
            <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
            <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
            <Setter Property="Padding" Value="6,3,5,3"/>
            <Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
            <Setter Property="ScrollViewer.PanningMode" Value="Both"/>
            <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
            <Setter Property="Template" Value="{StaticResource ComboBoxTemplate}"/>
            <Style.Triggers>
                <Trigger Property="IsEditable" Value="true">
                    <Setter Property="IsTabStop" Value="false"/>
                    <Setter Property="Padding" Value="2"/>
                    <Setter Property="Template" Value="{StaticResource ComboBoxEditableTemplate}"/>
                </Trigger>
            </Style.Triggers>
        </Style>
    </ComboBox.Resources>

</ComboBox>