树视图项目选择和鼠标按钮按下事件未触发

Question

我已经为树视图创建了视图模型。还创建了它们的绑定。 I created style trigger so that whenever a tree view item is selected, its background is changed.但是后台没有change.I处理tree view item选中的item和left mouse down事件来查看item是否被选中。但是这两个事件都没有触发。下面是XAML.

<TreeView Grid.Row="0" x:Name="TreeViewLocalSystem"  BorderBrush="Transparent" Panel.ZIndex="0">
     <TreeView.ItemContainerStyle>
        <Style TargetType="TreeViewItem">
            <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}" />
            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Background" Value="{StaticResource TextBoxBackgroundColor}"></Setter>
                </Trigger>
                <Trigger Property="IsSelected" Value="False">
                    <Setter Property="Background" Value="Transparent"></Setter>
                </Trigger>
            </Style.Triggers>
        </Style>
    </TreeView.ItemContainerStyle>
    <TreeView.Resources>
        <HierarchicalDataTemplate ItemsSource="{Binding Path=Children}"   DataType="{x:Type local:LocalTreeViewItemModel}">
            <TreeViewItem Header="{Binding Path=Text}"  Selected="TreeViewItem_Selected" HorizontalAlignment="Left" FontSize="{StaticResource MediumFontSize}" MouseLeftButtonDown="TreeViewItem_MouseLeftButtonDown" />
        </HierarchicalDataTemplate>
    </TreeView.Resources>
</TreeView>

我做错了什么？

编辑：我注意到的另一件事是，当我单击鼠标右键时会触发 MouseDown 事件，但不会在单击鼠标左键时触发。

Answer 1

您可以处理 TreeViewItem 的 PreviewMouseLeftButtonDown 事件：

<TreeView Grid.Row="0" x:Name="TreeViewLocalSystem"  BorderBrush="Transparent" Panel.ZIndex="0">
    <TreeView.ItemContainerStyle>
        <Style TargetType="TreeViewItem">
            <EventSetter Event="PreviewMouseLeftButtonDown" Handler="TreeViewLocalSystem_PreviewMouseLeftButtonDown" />
            <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}" />
            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Background" Value="{StaticResource TextBoxBackgroundColor}"></Setter>
                </Trigger>
                <Trigger Property="IsSelected" Value="False">
                    <Setter Property="Background" Value="Transparent"></Setter>
                </Trigger>
            </Style.Triggers>
        </Style>
    </TreeView.ItemContainerStyle>
    <TreeView.Resources>
        <HierarchicalDataTemplate ItemsSource="{Binding Path=Children}" DataType="{x:Type local:LocalTreeViewItemModel}">
            <TextBlock Text="{Binding Path=Text}" HorizontalAlignment="Left" FontSize="{StaticResource MediumFontSize}" />
        </HierarchicalDataTemplate>
    </TreeView.Resources>
</TreeView>

private void TreeViewLocalSystem_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    //...
}

树视图项目选择和鼠标按钮按下事件未触发

Tree View Item Selected and Mouse button down event not firing

c#

wpf

xaml

treeview

treeviewitem