更新2011-11-14
我最近再次遇到同样的要求,我对下面发布的解决方案不太满意。这是一种更好的方法来获得相同的行为,而无需重新模板化ComboBoxItem
。它使用一个DataTemplateSelector
首先,指定常规DataTemplate
, 下拉菜单DataTemplate
和ComboBoxItemTemplateSelector
在资源中ComboBox
。然后参考ComboBoxItemTemplateSelector
as a DynamicResource
for ItemTemplateSelector
<ComboBox ...
ItemTemplateSelector="{DynamicResource itemTemplateSelector}">
<ComboBox.Resources>
<DataTemplate x:Key="selectedTemplate">
<TextBlock Text="{Binding Path=ShortDescription}"/>
</DataTemplate>
<DataTemplate x:Key="dropDownTemplate">
<TextBlock Text="{Binding Path=FullDescription}"/>
</DataTemplate>
<local:ComboBoxItemTemplateSelector
x:Key="itemTemplateSelector"
SelectedTemplate="{StaticResource selectedTemplate}"
DropDownTemplate="{StaticResource dropDownTemplate}"/>
</ComboBox.Resources>
</ComboBox>
ComboBoxItemTemplateSelector
检查容器是否是 a 的子容器ComboBoxItem
,如果是,那么我们正在处理一个下拉项,否则它是ComboBox
.
public class ComboBoxItemTemplateSelector : DataTemplateSelector
{
public DataTemplate DropDownTemplate
{
get;
set;
}
public DataTemplate SelectedTemplate
{
get;
set;
}
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
ComboBoxItem comboBoxItem = VisualTreeHelpers.GetVisualParent<ComboBoxItem>(container);
if (comboBoxItem != null)
{
return DropDownTemplate;
}
return SelectedTemplate;
}
}
获取视觉父级
public static T GetVisualParent<T>(object childObject) where T : Visual
{
DependencyObject child = childObject as DependencyObject;
while ((child != null) && !(child is T))
{
child = VisualTreeHelper.GetParent(child);
}
return child as T;
}
旧的解决方案,需要重新模板化ComboBoxItem
<SolidColorBrush x:Key="SelectedBackgroundBrush" Color="#DDD" />
<SolidColorBrush x:Key="DisabledForegroundBrush" Color="#888" />
<ControlTemplate x:Key="FullDescriptionTemplate" TargetType="ComboBoxItem">
<Border Name="Border" Padding="2" SnapsToDevicePixels="true">
<StackPanel>
<TextBlock Text="{Binding Path=FullDescription}"/>
</StackPanel>
</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>
<ComboBox Name="c_comboBox" ItemsSource="{Binding}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=ShortDescription}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
<ComboBox.ItemContainerStyle>
<Style TargetType="{x:Type ComboBoxItem}">
<Setter Property="Template" Value="{StaticResource FullDescriptionTemplate}" />
</Style>
</ComboBox.ItemContainerStyle>
</ComboBox>
这会导致以下行为