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RE: Treeview Tutorial

pso — Thu, 09 Jun 2005 04:55:13 GMT


Private Sub button2_Click(sender As Object, _
  e As System.EventArgs) Handles button2.Click
Dim oNode As New TreeNode 
 oNode.Text = "My Node" 
  TreeView1.Nodes.Add(oNode) 
   oNode.Nodes.Add("") 
end sub

Private Sub button1_Click(sender As Object, _
  e As System.EventArgs) Handles button1.Click
   If treeView1.SelectedNode.IsExpanded Then
      treeView1.SelectedNode.Collapse()
      MessageBox.Show(treeView1.SelectedNode.Text & _ 
        " tree node collapsed.")
   Else
      treeView1.SelectedNode.Expand()
      MessageBox.Show(treeView1.SelectedNode.Text & _
        " tree node expanded.")
   End If
End Sub

I haven't done anything w/treeviews yet, but I've pieced the code from yours and msdn and here's a link for taking further steps:
http://www.vbdotnetheaven.com/Code/Jun2003/2083.asp

also, i'm thinking that it's not really neccessary to get Name properties, just use the text properties or hide info in the tag of node you add, then reference that node's tag or text from treevies selectednode event.

prob didn't help much.
good luck

RE: Treeview Tutorial

waynespangler — Wed, 08 Jun 2005 20:29:31 GMT

Thanks Mark but it put all them on the same level. I used:

oNode.Name = "Level1"
oNode.Text = "Level1"
TreeView1.Nodes.Add(oNode)
TreeView1.SelectedNode = oNode
oNode = New TreeNode
oNode.Name = "Level1b"
oNode.Text = "Level1b"
TreeView1.Nodes.Add(oNode)
oNode = New TreeNode
oNode.Name = "Level1a"
oNode.Text = "Level1a"
TreeView1.Nodes.Add(oNode)

I appreciate it though.

RE: Treeview Tutorial

Mark — Wed, 08 Jun 2005 18:25:25 GMT

I don't know of any tutorials and I'm just shooting in the dark here but I would try

TreeView1.SelectedNode = oNode
or
Set TreeView1.SelectedNode = oNode

Treeview Tutorial

waynespangler — Wed, 08 Jun 2005 12:23:01 GMT

Does anyone know or a REAL tutorial on Treeview. Not loading ado, xml, directories, etc. I mean one that explains the properties of the Treeview control. The above is about all I can find on the internet.

What I am trying to do is add a node to the treeview in a predetermined location. I then want to add two sub-nodes to the one just entered.

Dim oNode As New TreeNode

oNode.Name = "Level1"

TreeView1.Nodes.Add(oNode)

TreeView1.SelectedNode.Name = oNode.Name ==> Getting error here

TreeView1.Nodes.Add("Level1a")

TreeView1.Nodes.Add("level1b")

oNode = Nothing

The error is "NullReferencException was unhandeled." and "Object reference not set to an instance of an object."

Any tutorial on this subject would be greatly appreciated.