原文: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。
最后是广告：本大寨主征押寨夫人数名，名额无限，先到为大。