在WPF中，实现ComboBox多选，并且可以根据输入值动态显示下拉框
34浏览 · 2024-03-21 19:39:04
在WPF中，实现ComboBox多选可以通过设置ComboBox的IsEditable属性为True，并使用一个TextBlock来[显示](https://geek.csdn.net/educolumn/103ca72607c717122e068b9f06a24df6?spm=1055.2569.3001.10083)选中项，同时在ComboBox的Popup部分添加一个ItemsControl用于[显示](https://geek.csdn.net/educolumn/103ca72607c717122e068b9f06a24df6?spm=1055.2569.3001.10083)下拉选项。当用户输入时，我们可以[动态](https://geek.csdn.net/educolumn/08aef4ab97997f5b9ed71860c44e8258?spm=1055.2569.3001.10083)地过滤下拉选项。以下是一个简单的实现示例：
```xml
<ComboBox IsEditable="True"
Text="{Binding SelectedText}"
PreviewTextInput="ComboBox_PreviewTextInput"
PreviewKeyDown="ComboBox_PreviewKeyDown">
<ComboBox.Template>
<ControlTemplate TargetType="{x:Type ComboBox}">
<ToggleButton x:Name="ToggleButton"
Content="{TemplateBinding SelectionBoxItem}"
IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, Rel[ati](https://geek.csdn.net/educolumn/150d7073277950db5f09620704e791cf?spm=1055.2569.3001.10083)veSource={Rel[ati](https://geek.csdn.net/educolumn/150d7073277950db5f09620704e791cf?spm=1055.2569.3001.10083)veSource TemplatedParent}}"
ClickMode="Press"/>
<ContentPresenter x:Name="ContentSite"
IsHitTestVisible="False"
Content="{TemplateBinding SelectionBoxItem}"
ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
Margin="3,0,0,0"
VerticalAlignment="Center"
HorizontalAlignment="Left"/>
<Popup x:Name="Popup"
IsOpen="{TemplateBinding IsDropDownOpen}"
Placement="Bottom"
StaysOpen="False">
<Border x:Name="DropDownBorder"
Background="White"
BorderThickness="1"
BorderBrush="LightGray">
<ScrollViewer>
<ItemsControl x:Name="ItemsControl"
ItemsSource="{TemplateBinding ItemsSource}"
ItemTemplate="{TemplateBinding ItemTemplate}"
SelectionMode="Multiple"/>
</ScrollViewer>
</Border>
</Grid>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasItems" Value="False">
<Setter Property="Visibility" Value="Collapsed" TargetName="DropDownBorder"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Foreground" Value="Gray"/>
</Trigger>
<DataTrigger Binding="{Binding Path=Text.Length, RelativeSource={RelativeSource Self}}" Value="0">
<Setter Property="SelectedIndex" Value="-1" />
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</ComboBox.Template>
</ComboBox>