Dynamically Created TreeView not expanding/collapsing

[Chris]

Hi-

I'm running this database query where the results will be used to
populate my treeview.

For Each drPA As DataRow In dsMasterList.Ta bles(0).Rows
iRoot = iRoot + 1
nRootNode = New TreeNode(drPA(0 ), iRoot, "", "", "")
nRootNode.Selec tAction = TreeNodeSelectA ction.Expand
tvMasterList.No des.Add(nRootNo de)
For Each drSubject As DataRow In
dsMasterList.Ta bles(1).Rows
If (drSubject(1) = nRootNode.Text) Then
iSub = iSub + 1
nSubNode = New TreeNode(drSubj ect(1), iSub, "",
"", "")
nRootNode.Child Nodes.Add(nSubN ode)
For Each drTopic As DataRow In
dsMasterList.Ta bles(2).Rows
If (drTopic(1) = nSubNode.Text) Then
iTopic = iTopic + 1
nTopicNode = New TreeNode(drTopi c(1),
iTopic, "", "", "")
nSubNode.ChildN odes.Add(nTopic Node)
End If
Next
'nSubNode.Expan d()
End If
Next
'tvMasterList.N odes.Add(nRootN ode)
'nRootNode.Expa nd()
Next

If I uncomment the expand functions, I can see that my code works
nicely, and the treeview is populated correctly. But it won't expand
or collapse! When I try it I get the following error in the IE
'debugger':

"Childnodes .0 is null or not an object"

I'm really lost here, any help will be greatly appreciated.

[Chris]

This can be disregarded. I put the code inside of the form_load sub,
and it works perfectly.

On Feb 24, 4:46*pm, Chris <coz1...@gmail. comwrote:

Hi-

I'm running this database query where the resultswillbe used to
populate mytreeview.

For Each drPA As DataRow In dsMasterList.Ta bles(0).Rows
* * * * * * iRoot = iRoot + 1
* * * * * * nRootNode = New TreeNode(drPA(0 ), iRoot, "", "","")
* * * * * * nRootNode.Selec tAction = TreeNodeSelectA ction.Expand
* * * * * * tvMasterList.No des.Add(nRootNo de)
* * * * * * For Each drSubject As DataRow In
dsMasterList.Ta bles(1).Rows
* * * * * * * * If (drSubject(1) = nRootNode.Text) Then
* * * * * * * * * * iSub = iSub + 1
* * * * * * * * * * nSubNode = New TreeNode(drSubj ect(1), iSub, "",
"", "")
* * * * * * * * * * nRootNode.Child Nodes.Add(nSubN ode)
* * * * * * * * * * For Each drTopic As DataRow In
dsMasterList.Ta bles(2).Rows
* * * * * * * * * * * * If (drTopic(1) = nSubNode.Text) Then
* * * * * * * * * * * * * * iTopic = iTopic + 1
* * * * * * * * * * * * * * nTopicNode = NewTreeNode(drT opic(1),
iTopic, "", "", "")
* * * * * * * * * * * * * * nSubNode.ChildN odes.Add(nTopic Node)
* * * * * * * * * * * * End If
* * * * * * * * * * Next
* * * * * * * * * * 'nSubNode.Expan d()
* * * * * * * * End If
* * * * * * Next
* * * * * * 'tvMasterList.N odes.Add(nRootN ode)
* * * * * * 'nRootNode.Expa nd()
* * * * Next

If I uncomment theexpandfuncti ons, I can see that my code works
nicely, and thetreeviewis populated correctly. *But it won'texpand
or collapse! *When I try it I get the following error in the IE
'debugger':

"Childnodes .0 is null ornotan object"

I'm really lost here, any helpwillbe greatly appreciated.