WPF 多项选择下拉菜单

背景

项目中有一个多项选择筛选的功能, 由于筛选条件太多, 用户又习惯在平板上进行操作, 所以要求我们把checkbox 放到一个combobox里面, 然后checkbox的选项要在combobox里面显示出来, 再加一个全选功能. 喏, 就是这种效果.

实现

    首先, 实现思路是: 1. 自定义一个用户控件 2.添加一个combobox 3.重载combobox的item模板 4. 给模板中的checkbox添加点击事件.

    思路确定了,就开始实现功能.

  第一步 编辑xaml文件

<Grid>
        <ComboBox x:Name="CheckableCombo">
            <ComboBox.ItemTemplate>
                <HierarchicalDataTemplate>
                    <CheckBox Content="{Binding Title}"
                              IsChecked="{Binding IsSelected, Mode=TwoWay}"
                              Tag="{RelativeSource FindAncestor, AncestorType={x:Type ComboBox}}"
                              Click="Checkbox_OnClick"></CheckBox>
                </HierarchicalDataTemplate>
            </ComboBox.ItemTemplate>
            <ComboBox.Template>
                <ControlTemplate TargetType="ComboBox">
                    <Grid>
                        <ToggleButton Name="ToggleButton" 
                                      Style="{StaticResource ComboBoxToggleButton}"
                                      Focusable="False"
                                      IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
                        </ToggleButton>
                        <ContentPresenter x:Name="Presenter"
                                          IsHitTestVisible="False"
                                          Margin="3, 3, 23, 3"
                                          VerticalAlignment="Center"
                                          HorizontalAlignment="Left">
                            <ContentPresenter.Content>
                                <TextBlock TextTrimming="CharacterEllipsis"
                                           Text="{Binding Path=Text, Mode=TwoWay, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}}">
                                </TextBlock>
                            </ContentPresenter.Content>
                        </ContentPresenter>
                        <TextBox x:Name="EditableTextBox"
                        Style="{x:Null}" 
                        Template="{StaticResource ComboBoxTextBox}" 
                        HorizontalAlignment="Left" 
                        VerticalAlignment="Center" 
                        Margin="3,3,23,3"
                        Focusable="True" 
                        Background="Transparent"
                        Visibility="Hidden"
                        IsReadOnly="{TemplateBinding IsReadOnly}"/>
                        <Popup 
                        Name="Popup"
                        Placement="Bottom"
                        IsOpen="{TemplateBinding IsDropDownOpen}"
                        AllowsTransparency="True" 
                        Focusable="False"
                        PopupAnimation="Slide">
                            <Grid 
                                  Name="DropDown"
                                  SnapsToDevicePixels="True"                
                                  MinWidth="{TemplateBinding ActualWidth}"
                                  MaxHeight="{TemplateBinding MaxDropDownHeight}">
                                <Border 
                                    x:Name="DropDownBorder"
                                    Background="{StaticResource WindowBackgroundBrush}"
                                    BorderThickness="1"/>
                                <ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True" DataContext="{Binding}">
                                    <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
                                </ScrollViewer>
                            </Grid>
                        </Popup>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="HasItems" Value="false">
                            <Setter TargetName="DropDownBorder" Property="MinHeight" Value="95"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
                        </Trigger>
                        <Trigger Property="IsGrouping" Value="true">
                            <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                        </Trigger>
                        <Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="true">
                            <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="4"/>
                            <Setter TargetName="DropDownBorder" Property="Margin" Value="0,2,0,0"/>
                        </Trigger>
                        <Trigger Property="IsEditable"
                   Value="true">
                            <Setter Property="IsTabStop" Value="false"/>
                            <Setter TargetName="EditableTextBox" Property="Visibility"    Value="Visible"/>
                            <Setter TargetName="Presenter" Property="Visibility" Value="Hidden"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </ComboBox.Template>
        </ComboBox>
    </Grid>

这里的重点在于ItemTemplate里的 checkbox 和 ComboBox.Template 里的 ContentPresenter.Content –> TextBlock 这么长的代码其实主要是重写这两个地方, 改变控件原有的功能. 其中checkbox 的content 绑定的Title和IsSelected 是从绑定的数据源里面提取. 通常itemsource绑定的都是IEnumerable类型, 所以要求你的数据源一定是一个很多具有这两个属性的实例的聚合.

第二步 写数据模型

public class MultipleCheckboxModel : ModelBase<MultipleCheckboxModel>
    {
        public Guid Id { get; set; }

        public string Title { get; set; }

        private bool _isSelected;

        public bool IsSelected
        {
            get { return _isSelected; }
            set
            {
                _isSelected = value;
                NotifyPropertyChanged(x => x.IsSelected);
            }
        }
    }

这里面的ModelBase 继承了INotifyPropertyChanged 用来实现数据联动.  NotifyErrorsChanged 也是ModelBase里封装的方法. 因为这个不是本文章的重点, 就不贴出来了, 大家可以直接继承 INotifyPropertyChanged 来实现联动.

第三步 写依赖属性

#region Dependency Properties

        public IEnumerable<MultipleCheckboxModel> ItemsSource
        {
            get { return (IEnumerable<MultipleCheckboxModel>)GetValue(ItemsSourceProperty); }
            set
            {
                SetValue(ItemsSourceProperty, value);
                SetText();
            }
        }

        public static readonly DependencyProperty ItemsSourceProperty =
            DependencyProperty.Register("ItemsSource", typeof(object), typeof(MultipleCheckbox), new FrameworkPropertyMetadata(null, ItemsSourcePropertyChangedCallback));

        private static void ItemsSourcePropertyChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            var multioleCheckbox = dependencyObject as MultipleCheckbox;
            if (multioleCheckbox == null) return;
            multioleCheckbox.CheckableCombo.ItemsSource = multioleCheckbox.ItemsSource;
        }

        public string Text
        {
            get { return (string)GetValue(TextProperty); }
            set { SetValue(TextProperty, value); }
        }

        public static readonly DependencyProperty TextProperty =
            DependencyProperty.Register("Text", typeof(string), typeof(MultipleCheckbox), new FrameworkPropertyMetadata("", TextPropertyChangedCallback));

        private static void TextPropertyChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
        {
            var multioleCheckbox = dependencyObject as MultipleCheckbox;
            if (multioleCheckbox == null) return;
        }

        public string DefaultText
        {
            get { return (string)GetValue(DefaultTextProperty); }
            set { SetValue(DefaultTextProperty, value); }
        }

        public static readonly DependencyProperty DefaultTextProperty =
            DependencyProperty.Register("DefaultText", typeof(string), typeof(MultipleCheckbox), new UIPropertyMetadata(string.Empty));

        #endregion

依赖属性主要就这三个 使用时可以直接在view端进行binding没什么好说的

第四步 checkbox的点击事件

#region Event

        private void Checkbox_OnClick(object sender, RoutedEventArgs e)
        {
            var checkbox = sender as CheckBox;
            if (checkbox == null) return;
            if ((string) checkbox.Content == "All")
            {
                Text = "";
                if (checkbox.IsChecked != null && checkbox.IsChecked.Value)
                {
                    ItemsSource.ForEach(x =>
                    {
                        x.IsSelected = true;
                        Text = "All";
                    });
                }
                else
                {
                    ItemsSource.ForEach(x =>
                    {
                        x.IsSelected = false;
                        Text = "None";
                    });
                }
            }
            else
            {
                SetText();
            }
            
        }

        #endregion

这里的All 就是实现全选功能的, 感觉实现方式有些low, (｡>ㅅ<｡) 主要是时间有点急, 稍后慢慢优化.

然后是前面用到的私有方法

#region Private Method

        private void SetText()
        {
            Text = "";
            var all = ItemsSource.FirstOrDefault(x => x.Title == "All");
            foreach (var item in ItemsSource)
            {


                if (item.IsSelected && item.Title != "All")
                {
                    Text += item.Title + ",";
                }
                else if(all != null)
                {
                    if (all.IsSelected)
                        all.IsSelected = false;
                }
            }                

            Text = string.IsNullOrEmpty(Text) ? DefaultText : Text.TrimEnd(new[] { ',' });
        }

        #endregion

至此控件功能完成了

第五步就是使用

<user:MultipleCheckbox DefaultText="Choose" ItemsSource="{Binding OtBeds}" />

private ObservableCollection<MultipleCheckboxModel> _otBeds;       
public ObservableCollection<MultipleCheckboxModel> OtBeds
{
    get { return _otBeds ?? (_otBeds = new ObservableCollection<MultipleCheckboxModel>()); }
}

// 初始化OtBeds的时候 不要忘了加一个 
OtBeds.Add(new MultipleCheckboxModel {Id = Guid.Empty, Title = "All", IsSelected = true}); //惨不忍睹 这个应该写在 控件里面

附录 前面xaml用到的样式

<UserControl.Resources>
        <LinearGradientBrush x:Key="NormalBrush" StartPoint="0,0" EndPoint="0,1">
            <GradientBrush.GradientStops>
                <GradientStopCollection>
                    <GradientStop Color="#FFF" Offset="0.0"/>
                    <GradientStop Color="#CCC" Offset="1.0"/>
                </GradientStopCollection>
            </GradientBrush.GradientStops>
        </LinearGradientBrush>

        <LinearGradientBrush x:Key="NormalBorderBrush" StartPoint="0,0" EndPoint="0,1">
            <GradientBrush.GradientStops>
                <GradientStopCollection>
                    <GradientStop Color="#CCC" Offset="0.0"/>
                    <GradientStop Color="#444" Offset="1.0"/>
                </GradientStopCollection>
            </GradientBrush.GradientStops>
        </LinearGradientBrush>

        <SolidColorBrush x:Key="GlyphBrush" Color="#444" />

        <LinearGradientBrush x:Key="DarkBrush" StartPoint="0,0" EndPoint="0,1">
            <GradientBrush.GradientStops>
                <GradientStopCollection>
                    <GradientStop Color="#FFF" Offset="0.0"/>
                    <GradientStop Color="#AAA" Offset="1.0"/>
                </GradientStopCollection>
            </GradientBrush.GradientStops>
        </LinearGradientBrush>

        <LinearGradientBrush x:Key="PressedBrush" StartPoint="0,0" EndPoint="0,1">
            <GradientBrush.GradientStops>
                <GradientStopCollection>
                    <GradientStop Color="#BBB" Offset="0.0"/>
                    <GradientStop Color="#EEE" Offset="0.1"/>
                    <GradientStop Color="#EEE" Offset="0.9"/>
                    <GradientStop Color="#FFF" Offset="1.0"/>
                </GradientStopCollection>
            </GradientBrush.GradientStops>
        </LinearGradientBrush>

        <SolidColorBrush x:Key="DisabledForegroundBrush" Color="#888" />

        <SolidColorBrush x:Key="DisabledBackgroundBrush" Color="#EEE" />

        <SolidColorBrush x:Key="WindowBackgroundBrush" Color="#FFF" />

        <SolidColorBrush x:Key="SelectedBackgroundBrush" Color="#DDD" />

        <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="#FF3C77DD"/>

        <ControlTemplate x:Key="ComboBoxTextBox" TargetType="TextBox">
            <Border x:Name="PART_ContentHost" Focusable="False" Background="{TemplateBinding Background}" />
        </ControlTemplate>
        <Style x:Key="ComboBoxToggleButton" TargetType="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" CornerRadius="5" BorderBrush="{StaticResource ComboBox.Static.Border}" BorderThickness="{TemplateBinding BorderThickness}" SnapsToDevicePixels="true" Background="White">
                            <Border x:Name="splitBorder"  BorderBrush="Transparent" BorderThickness="1" HorizontalAlignment="Right" Margin="0,0,2,0" SnapsToDevicePixels="true" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}">
                                <Path x:Name="arrow"  Data="F1 M 0,0 L 3.667,2.66665 L 7.3334,0 L 7.3334,-1.78168 L 3.6667,0.88501 L0,-1.78168 L0,0 Z" Fill="{StaticResource ComboBox.Static.Glyph}" HorizontalAlignment="Center"  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>
        <Style x:Key="{x:Type ComboBoxItem}" TargetType="ComboBoxItem">
            <Setter Property="SnapsToDevicePixels" Value="true"/>
            <Setter Property="OverridesDefaultStyle" Value="true"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ComboBoxItem">
                        <Border 
                          Name="Border"
                          Padding="2"
                          SnapsToDevicePixels="true">
                            <ContentPresenter />
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsHighlighted" Value="true">
                                <Setter TargetName="Border" Property="Background" Value="{StaticResource SelectedBackgroundBrush}"/>
                            </Trigger>
                            <Trigger Property="IsEnabled" Value="false">
                                <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </UserControl.Resources>

参考: http://blogs.microsoft.co.il/justguy/2009/01/19/wpf-combobox-with-checkboxes-as-items-it-will-even-update-on-the-fly/