WPF界面设计技巧（8）—自制山寨版CheckListBox

近年来IT市场山寨横行啊，我们今天也来发扬一下山寨精神，搞个自制的CheckListBox出来。

喏，CheckListBox 就是下面这玩意啦：

为什么要搞它？我们是山寨耶，说搞谁就搞谁！

我也不知道为什么，WPF里没有提供 CheckListBox 控件，但凭借WPF强大的外观定制能力，我们可以轻松的创制一个自己的 CheckListBox 。

CheckListBox 的基本功能其实和 ListBox 没有太大出入，只要将普通的ListBox 的选择模式设为多选，它就能基本实现 CheckListBox 的功用了，只不过从用户角度来说，它的使用方式不如 CheckListBox 看起来那么明确而已。

我们接下来就仅仅采用外观修改的方法，将 ListBox 与 CheckBox 拼插，打造出无敌山寨版 CheckListBox 。

首先在窗体设计器中建立一个ListBox，并为之填入一些内容项：

然后我们把第四讲时的列表样式代码COPY到App.xaml里去：

Code
         <!--ListBox样式-->
        <Style TargetType="ListBox">
            <Setter Property="BorderBrush" Value="#BDD4F1"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Background" Value="#F8F7F5"/>
            <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden"/>
            <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
            <Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
            <Setter Property="VerticalContentAlignment" Value="Center"/>
        </Style>
        <!--ListBoxItem样式-->
        <Style TargetType="ListBoxItem">
            <Setter Property="Foreground" Value="#B5BABF"/>
            <Setter Property="OverridesDefaultStyle" Value="True"/>
            <Setter Property="Height" Value="24"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ListBoxItem">
                        <Border Name="back" BorderBrush="#F8F7F5" BorderThickness="0,1,0,1">
                            <Border.Background>
                                <LinearGradientBrush StartPoint="0,0" EndPoint="0,1">
                                    <GradientBrush.GradientStops>
                                        <GradientStopCollection>
                                            <GradientStop Color="#F8F7F5" Offset="0.0"/>
                                            <GradientStop Color="#F8F7F5" Offset="0.5"/>
                                            <GradientStop Color="#F8F7F5" Offset="0.51"/>
                                            <GradientStop Color="#F8F7F5" Offset="1"/>
                                        </GradientStopCollection>
                                    </GradientBrush.GradientStops>
                                </LinearGradientBrush>
                            </Border.Background>
                            <ContentPresenter Margin="2" VerticalAlignment="Center"/>
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsSelected" Value="True">
                                <Trigger.EnterActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <DoubleAnimation To="32" Duration="0:0:0.3" Storyboard.TargetProperty="Height"/>
                                            <ColorAnimation To="#F3C37C" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" />
                                            <ColorAnimation To="#952B00" Duration="0:0:0.2" Storyboard.TargetProperty="(ListBoxItem.Foreground).(SolidColorBrush.Color)" />
                                            <ColorAnimation To="#FFF" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[0].(GradientStop.Color)" />
                                            <ColorAnimation To="#FFEF99" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[1].(GradientStop.Color)" />
                                            <ColorAnimation To="#FFE13F" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[2].(GradientStop.Color)" />
                                            <ColorAnimation To="#FFF3B0" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[3].(GradientStop.Color)" />
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.EnterActions>
                                <Trigger.ExitActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <DoubleAnimation BeginTime="0:0:0.4" Duration="0:0:0.2" Storyboard.TargetProperty="Height"/>
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetProperty="(ListBoxItem.Foreground).(SolidColorBrush.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[0].(GradientStop.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[1].(GradientStop.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[2].(GradientStop.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[3].(GradientStop.Color)" />
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.ExitActions>
                            </Trigger>
                            <Trigger Property="IsMouseOver" Value="True">
                                <Trigger.EnterActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ColorAnimation To="#D8E6F5" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" />
                                            <ColorAnimation To="#617A98" Duration="0:0:0.2" Storyboard.TargetProperty="(ListBoxItem.Foreground).(SolidColorBrush.Color)" />
                                            <ColorAnimation To="#F6F9FD" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[0].(GradientStop.Color)" />
                                            <ColorAnimation To="#E0EBF7" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[1].(GradientStop.Color)" />
                                            <ColorAnimation To="#D7E5F6" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[2].(GradientStop.Color)" />
                                            <ColorAnimation To="#F6F9FD" Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[3].(GradientStop.Color)" />
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.EnterActions>
                                <Trigger.ExitActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetProperty="(ListBoxItem.Foreground).(SolidColorBrush.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[0].(GradientStop.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[1].(GradientStop.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[2].(GradientStop.Color)" />
                                            <ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="back" Storyboard.TargetProperty="(Border.Background).(LinearGradientBrush.GradientStops)[3].(GradientStop.Color)" />
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.ExitActions>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

修改 ContentPresenter 元素处的代码，用一个 CheckBox 将其包起来：

< CheckBox  Margin ="2,0,0,0"  VerticalAlignment ="Center"  IsChecked =" {Binding RelativeSource={RelativeSource TemplatedParent},Path=IsSelected,Mode=TwoWay} " >
   < ContentPresenter  Margin ="2" />
</ CheckBox >

从上面的代码我们可以看到，CheckBox 的 IsChecked 属性双向绑定到了列表项的 IsSelected 属性上，这时勾选 CheckBox 就会使列表项被选中，反之亦然，这就是模拟 CheckListBox 的技术核心所在。

现在我们的界面是这个样子了：

再完成最后一步，修改 ListBox 的选取模式为多选：

OK，运行一下就是这样了：

简直和真的一样！

如何通过代码获取选定的项呢？这样就可以了：listBox1.SelectedItems

再附送一个小经验：当你程序运行后，在窗体的“Initialized”事件中自动从配置文件读取到数据，并将之绑定到 ListBox 后，想要将其默认设为全选的话，应当在窗体的“ContentRendered”事件中执行全选命令“listBox1.SelectAll()”，在“Loaded”、“Initialized”等事件中执行均无效，推测可能是控件载入到绑定数据之间会存在一定延迟。

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源代码下载