vb.net treeview add sibling node

Question

In vs2017, vb.net using windows forms, I would like to add a sibling node to a treeview. I upgraded from vs 2010 and the treeview control would use tvwPrevious or tvwNext as the relationship so I am looking for an equivalent with the newer Treeview control.

See attached treeview snippet- I highlighted the "Limited Partnership..." node and I am trying to add a new node directly below or above that selected node. The code I have now adds the new node to the very bottom of the tree:

TreeView1.Nodes.Insert(TreeView1.SelectedNode.Index, sNewKey, "PREVIOUS").NodeFont = New Font(TreeView1.Font, FontStyle.Bold)

I found various workarounds on the web, but nothing seems to work.

1 solution put the new node as a child to the selected node.

Another solution added the new node to the very end of the tree:
TreeView1.BeginUpdate()
TreeView1.Nodes.Insert(663, sNewKey, "PREVIOUS").NodeFont = New Font(TreeView1.Font, FontStyle.Bold) 'where 663 is the index of the selected node
TreeView1.EndUpdate()

Any ideas?

Answer 1

Hi,
Thanks for your feedback.
The code you shared have some problems.

How do I insert a new node before or after the node the user selected?

You can refer to the following code to do this.

    Dim i As Integer = 1  
    Dim j As Integer = 1  
    Dim sNewKey As String = "key"  
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click  
        If TreeView1.SelectedNode.Parent Is Nothing Then  
            If TreeView1.SelectedNode.Index = 0 Then  
                TreeView1.Nodes.Insert(0, sNewKey, "N" + i.ToString()).NodeFont = New Font(TreeView1.Font, FontStyle.Bold)  
            Else  
                TreeView1.Nodes.Insert(TreeView1.SelectedNode.Index, sNewKey, "N" + i.ToString()).NodeFont = New Font(TreeView1.Font, FontStyle.Bold)  
            End If  
        ElseIf TreeView1.SelectedNode.Index = 0 Then  
            TreeView1.SelectedNode.Parent.Nodes.Insert(0, sNewKey, "N" + i.ToString()).NodeFont = New Font(TreeView1.Font, FontStyle.Bold)  
        Else  
            TreeView1.SelectedNode.Parent.Nodes.Insert(TreeView1.SelectedNode.Index, sNewKey, "N" + i.ToString()).NodeFont = New Font(TreeView1.Font, FontStyle.Bold)  
        End If  
        i += 1  
    End Sub  
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click  
        If TreeView1.SelectedNode.Parent Is Nothing Then  
            TreeView1.Nodes.Insert(TreeView1.SelectedNode.Index + 1, sNewKey, "L" + j.ToString()).NodeFont = New Font(TreeView1.Font, FontStyle.Bold)  
        Else  
            TreeView1.SelectedNode.Parent.Nodes.Insert(TreeView1.SelectedNode.Index + 1, sNewKey, "L" + j.ToString()).NodeFont = New Font(TreeView1.Font, FontStyle.Bold)  
        End If  
        j += 1  
    End Sub  

Result of my test.

Hope it could be helpful.
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Answer 2

Hi JosephMancini-5735,
Thank you for posting here.

I would like to add a sibling node to a treeview

I make a test on my side and add some treenodes into TreeView.

Then I use the following code to add a sibling node to 'Great Grandchild'.

TreeView1.Nodes(0).Nodes(1).Nodes(0).Nodes().Insert(1, (New TreeNode("Inserted node")))  

Result of my test.

Hope it could be helpful.

Answer 3

I see what you are doing, but I don't know how that would work for me. I need to detect what node the user selected on the tree, and add a new node before or after the node they selected. Your example drills down to that node, node by node, and inserts a new node. I can get the index of the node that the user selected. How do I insert a new node before or after the node the user selected? When I use the example on this link below, my new node gets inserted at the very bottom of my tree. I need a new node created at a specific location, based on the user selection.

https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.treenodecollection.insert?view=netcore-3.1#System_Windows_Forms_TreeNodeCollection_Insert_System_Int32_System_String_System_String_

Answer 4

I did some more digging around today and found this link below with a solution in the last reply.
https://www.vbforums.com/showthread.php?375905-Add-node-directly-after-selected-node

So I applied this to my code, and came up with this to add the Next Sibling. It seems to work, as does adding a previous sibling, but perhaps there is a better way?

            If TreeView1.SelectedNode.Parent Is Nothing Then 'there is no parent of the selected node
                'If we are on a parent/header node, then we use this line, which was the original line of code we were using
                TreeView1.Nodes.Add(sNewKey, "Next").NodeFont = New Font(TreeView1.Font, FontStyle.Bold)
            Else 'we are adding to a parent/child/grandchild in the tree
                TreeView1.SelectedNode.Parent.Nodes.Insert(TreeView1.SelectedNode.Index + 1, sNewKey, "Next").NodeFont = New Font(TreeView1.Font, FontStyle.Bold)
            End If

Answer 5

I tweaked your answer just a bit to display Next/Previous in the new node, but the answer does work for me as presented. Thank you.