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:
<!--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:
<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。