C# – Right click select on .Net TreeNode

ctreeviewuser interfacewinforms

I am trying to show a popup menu on my treeview when users right click – allowing them to choose context sensitive actions to apply against the selected node.

At the moment the user has to left click node and then right click to choose.

Is it possible to make a right click on a node select that node – and if so what is the best method to do this.

Best Answer

Both left and right clicks fire a click event and cause the selection to change. However, in certain circumstances (that I haven't yet bothered to trace down) the selection will change from the node that was right clicked to the originally selected node.

In order to make sure that the right click changes the selection, you can forcibly change the selected node by using the MouseDown event:

treeView.MouseDown += (sender, args) =>
    treeView.SelectedNode = treeView.GetNodeAt(args.X, args.Y);

A little better, as one of the other posters pointed out, is to use the NodeMouseClick event:

treeView.NodeMouseClick += (sender, args) => treeView.SelectedNode = args.Node;

Related Solutions

Wpf – Select TreeView Node on right click before displaying ContextMenu

Depending on the way the tree was populated, the sender and the e.Source values may vary.

One of the possible solutions is to use e.OriginalSource and find TreeViewItem using the VisualTreeHelper:

private void OnPreviewMouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
    TreeViewItem treeViewItem = VisualUpwardSearch(e.OriginalSource as DependencyObject);

    if (treeViewItem != null)
    {
        treeViewItem.Focus();
        e.Handled = true;
    }
}

static TreeViewItem VisualUpwardSearch(DependencyObject source)
{
    while (source != null && !(source is TreeViewItem))
        source = VisualTreeHelper.GetParent(source);

    return source as TreeViewItem;
}

Wpf – In WPF, how to select the treeview item under the cursor on right-click

That's because the ItemContainerStyle is not inherited by the child nodes. You need to add the same EventSetter on the ItemContainerStyle o your HierarchicalDataTemplate.

<HierarchicalDataTemplate x:Key="treeHierarchicalDataTemplate" 
                          ItemsSource="{Binding Path=ChildMeetingItems}">
    <HierarchicalDataTemplate.Triggers>
        <DataTrigger Binding="{Binding Path=Red}" Value="True">
            <Setter TargetName="img" Property="Image.Source" Value="pack://siteoforigin:,,,/images/bookRed.png"></Setter>
        </DataTrigger>
    </HierarchicalDataTemplate.Triggers>
    <StackPanel 
        x:Name="treeViewItemPanel"
        Background="Transparent"
        Orientation="Horizontal">
        <Image Width="16" Height="16"  x:Name="img" Margin="0,0,4,0" Source="pack://siteoforigin:,,,/images/bookGreen.png"></Image>
        <TextBlock Foreground="DarkGray" Text="{Binding DisplayIndex}" Margin="0,0,5,0"></TextBlock>
        <TextBlock Text="{Binding Summary}"></TextBlock>
    </StackPanel>

<HierarchicalDataTemplate.ItemContainerStyle>
                <Style TargetType="{x:Type TreeViewItem}">
                    <EventSetter Event="TreeViewItem.PreviewMouseRightButtonDown" Handler="trv_PreviewMouseRightButtonDown"/>                    
                </Style>
            </HierarchicalDataTemplate.ItemContainerStyle>
</HierarchicalDataTemplate>

Best Answer

Related Solutions

Wpf – Select TreeView Node on right click before displaying ContextMenu

Wpf – In WPF, how to select the treeview item under the cursor on right-click

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