将命令附加到树视图子视图-对于嵌套的子视图不同
本文关键字:视图 嵌套 于嵌套 命令 | 更新日期: 2023-09-27 18:16:28
我使用的代码从这里:WPF/MVVM -如何处理双击在ViewModel中的TreeViewItems ?,从接受的答案。我的xaml是这样的:
<TreeView CommandBehaviors:MouseDoubleClick.Command="{Binding ConnectServer}" CommandBehaviors:MouseDoubleClick.CommandParameter="{Binding Path=SelectedItem, RelativeSource={RelativeSource Self}}"
Grid.Column="0" HorizontalAlignment="Stretch" DockPanel.Dock="Left" ItemsSource="{Binding Path=ServerItems, UpdateSourceTrigger=PropertyChanged}">
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="CommandBehaviors:MouseDoubleClick.Command" Value="{Binding ConnectDb}"/>
<Setter Property="CommandBehaviors:MouseDoubleClick.CommandParameter" Value="{Binding Path=SelectedItem, RelativeSource={RelativeSource Self}}"/>
</Style>
</TreeView.ItemContainerStyle>
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Databases}">
<TextBlock Text="{Binding}" />
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
Style标签附加的命令不工作,它不应该,因为已经有一个命令附加在TreeView标签级别。我要做的是对顶层子节点执行一个命令,对低层子节点执行另一个命令。我怎么做呢?
编辑:所以,正如Viv建议的那样-我如何检查treeviewitem是否是根节点?
类似于
<Window.Resources>
<CommandBehaviors:IsRootNodeConverter x:Key="IsRootNodeConverter" />
</Window.Resources>
<Grid>
<TreeView>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="CommandBehaviors:MouseDoubleClick.Command"
Value="{Binding ConnectDb}" />
<Setter Property="CommandBehaviors:MouseDoubleClick.CommandParameter"
Value="{Binding Path=SelectedItem,
RelativeSource={RelativeSource Self}}" />
<Setter Property="Foreground"
Value="Black" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=.,
RelativeSource={RelativeSource Self},
Converter={StaticResource IsRootNodeConverter}}"
Value="True">
<Setter Property="CommandBehaviors:MouseDoubleClick.Command"
Value="{Binding ConnectServer}" />
<Setter Property="Foreground"
Value="Tomato" />
</DataTrigger>
</Style.Triggers>
</Style>
</TreeView.ItemContainerStyle>
<TreeView.ItemTemplate>
<HierarchicalDataTemplate>
<!--<TreeViewItem>-->
<TextBlock Text="{Binding}" />
<!--</TreeViewItem>-->
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
<TreeViewItem Header="1">
<TreeViewItem Header="A" />
<TreeViewItem Header="B">
<TreeViewItem Header="AA" />
<TreeViewItem Header="AB" />
<TreeViewItem Header="AC" />
</TreeViewItem>
<TreeViewItem Header="C" />
</TreeViewItem>
</TreeView>
</Grid>
和转换器:
class IsRootNodeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture) {
TreeViewItem item = value as TreeViewItem;
if (item == null || item.Parent == null)
return false;
return !Object.ReferenceEquals(value.GetType(), item.Parent.GetType());
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) {
throw new NotImplementedException();
}
}
我故意从Style
Trigger
中省略了CommandBehaviors:MouseDoubleClick.CommandParameter
,因为它似乎与默认值没有变化。刚刚添加了一个Foreground
属性用于测试,您也可以删除它