dynamically remove TreeNodes

Question

This one is giving me a real headache for the last couple of days.
I'm wriing a TreeView and this is how it should work. Tree view has set of nodes and each node contains set of other nodes as well.
Based on the logged in users access rights I want to remove some nodes.
I'm getting access rights as a string from the DB and looks like this

frmAdminRegisterWindow,Admin,1,;frmAdminUser,Admin,1,;Admin,,0,;
<NodeName>,<ParentNodeName>,<Visible>

Here is the deal
I want to remove the treeNodes and I tried this code

                if (readOnly == "0")
                {
                    treeView1.Nodes[nodeName].Remove();
                }

which gives an exception to me stating that "Object reference not set to an instance of an object."

This is the code segment I have above that if statement to add the Nodes

            treeView1.Nodes.Clear();

            //NOTE: Node name has to be applicatin wide unique name

            //User Administration
            TreeNode Admin = treeView1.Nodes.Add("Admin");
            Admin.Nodes.Add("frmAdminUser", "User");
            Admin.Nodes.Add("frmAdminRegisterWindow", "Register Window");

So if the nodeName = Admin it should remove the TreeNode Admin, but instead I'm getting the above exception.

Any idea?

garuka · Answer

I got it. This code did the trick if (parent == ) { if (readOnly == 0) { treeView1.Nodes[nodeName].Remove(); } } else { if (readOnly == 0) { treeView1.Nodes[parent].Nodes[nodeName].Remove(); } }

garuka · Answer

of course. I forgot to add that the name to Admin. Thanks a lot. Now it works perfectly for admin. But part of my problem still remains. Even I can remove top level nodes which are directly under TreeView root its nor possible to remove nodes inside Admin and such first level nodes. Now I can remove everything under Admin my removing Admin. But say I want to delete the frmAdminUser only. How can I do that. Same logic doesn't work there.

Ben · Answer

treeview.Nodes.Add(Admin) sets the Text property of the node to Admin but the name will be  (empty string) unless you programmatically change it using : TreeView tV = new TreeView(); TreeNode tN = tV.Nodes.Add(Admin); tN.Name = Admin; The name of the node being set Nodes[Admin] won't return a null anymore. Hope it helps.