Treeview hell

Question

Hi I'm trying to use a treeview control in this little app and it's giving me a headache. Basically I want to programatically add a child to a node but only the last child in the nodecollection for the control. Imagine the structure is like this: item1 -item2 --item3 ---item4 I want the user to be able to add a child but only to in this case item4. There's an abundance of examples on how to add a node using selectedNode.nodes.add but that requires user interaction. Hopefully I explained myself alright.

LoCellCount · Answer

Brilliant that's the bugger. Thanks a lot for your help.

spgilmore · Answer

You have to start with the treeview's root Nodes property and iterate through each node in it. For each node in the nodelist do the same thing with that node's Nodelist. This is called recursion. I created a form with two buttons and a treeview. The first button populates the treeview with some plain data and the second adds nodes to the existing leaf nodes (leaf nodes are nodes with no children). private void button1_Click(object sender EventArgs e) { TreeNode lCurrentNode lNewNode; for (int x = 0; x < 4; x++) { lCurrentNode = new TreeNode(Item  + x.ToString()); treeView1.Nodes.Add(lCurrentNode); for (int y = 0; y < 4; y++) { lNewNode = new TreeNode(Item  + y.ToString()); lCurrentNode.Nodes.Add(lNewNode); lCurrentNode = lNewNode; } } treeView1.Refresh(); } private void WalkNodes(TreeNodeCollection aNodes) { foreach (TreeNode lNode in aNodes) { if (lNode.Nodes.Count == 0) //We've found a leaf node. Do something to it. lNode.Nodes.Add(new TreeNode(NewLeaf)); else //Node has children. Walk those too. WalkNodes(lNode.Nodes); } } private void button2_Click(object sender EventArgs e) { WalkNodes(treeView1.Nodes); }