[RESOLVED] Adding a child to root only in a treeview

Hi,

I'm really new at VB. This thread really helped me figure out how to add nodes and rootnodes, but I don't want my treeview to ever go beyond the first level of children (no child added to a child). My first thought was to try and figure out if a child was selected and popup a message box telling the user to choose a rootnode, but now I am leaning toward just selecting the rootnode for the user and adding the child sibling node.

Can anyone point me in the right direction with this?

Thanks!

This code will add a Root Node to a treeview and then it will add child nodes every time Button2 is clicked:

VB Code:

Public Class Form1
    Dim Selectednode As TreeNode
 
    Private Sub AddChild(ByVal CurrentNode As TreeNode, _
                       ByVal strText As String)
        Dim tvwnode As New TreeNode
        tvwnode.Text = strText
        CurrentNode.Nodes.Add(tvwnode)
        TreeView1.ExpandAll()
    End Sub
 
    Private Sub Button1_Click_1(ByVal sender As System.Object, _
                ByVal e As System.EventArgs) Handles Button1.Click
        'Adds the Root Node
        Dim rootnode As TreeNode
        rootnode = Me.TreeView1.Nodes.Add("RootNode", "Root")
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, _
                ByVal e As System.EventArgs) Handles Button2.Click
        'Adds Children nodes to Root
        Selectednode = Me.TreeView1.Nodes(0)
        AddChild(Selectednode, "Child")
    End Sub
End Class

All you have to do is test the Parent property of a TreeNode. If it is Nothing then it is a root node, otherwise it is a child node. In the AfterSelect event handler of the TreeView, test the parent property of the selected node and disable your Add Node button, or whatever you use, if the node is a child.

thanks Mark,

That is a step in the right direction for me, but it is only adding children to the original root. I probably wasn't clear that I will have several root nodes. I see where I can use this though, I just need a way to figure out what level my rootnodes are for Selectednode = Me.TreeView1.Nodes(0).

Each treenode has it's own childnodes. All you have to do to add nodes to the treeview rootnode is:

VB Code:

TreeView1.Nodes(0).Nodes.Add("My New Node")

This will add the node to the rootnode, first node of the treeview, no matter what node is selected. Just incriment the index everytime you need to add it to a different rootnode.

I hope this helps.

jmcilhinney,

that did it for me, thank you.

here is what I ended up with...using a message box. I like the idea of disabling the "add child" button, but for now I'm cooking with gas.

VB Code:

'handles the button click for adding a new ditch section to the tree view.
    Private Sub cmdSectAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSectAdd.Click
        '// add some items
        If (Not tvwDitch.SelectedNode.Parent Is Nothing) Then
            MessageBox.Show("Please select a Ditch to add Section to, and try again.", "Select a Ditch", MessageBoxButtons.OK)
        Else
            AddChild(Selectednode, "Section1")
        End If
    End Sub
 
    Private Sub AddChild(ByVal CurrentNode As TreeNode, _
                   ByVal strText As String)
        Dim tvwnode As New TreeNode
        With tvwnode
            .Text = strText
        End With
        CurrentNode.Nodes.Add(tvwnode)
    End Sub