Add treeview control via tool box
go to form load function
put treeview control name "treeView1"
add following code i add node dynamically
TreeNode Main1 = new TreeNode("Main1");
TreeNode Main2 = new TreeNode("Main2");
TreeNode Main3 = new TreeNode("Main3");
TreeNode Sub1 = new TreeNode("Sub1");
TreeNode Sub2 = new TreeNode("Sub2");
TreeNode Sub3 = new TreeNode("Sub3");
TreeNode Sub4 = new TreeNode("Sub4");
treeView1.Nodes.Add(Main1);
treeView1.Nodes.Add(Main2);
treeView1.Nodes.Add(Main3);
treeView1.Nodes[0].Nodes.Add(Sub1);
treeView1.Nodes[0].Nodes.Add(Sub2);
treeView1.Nodes[1].Nodes.Add(Sub3);
treeView1.Nodes[2].Nodes.Add(Sub4);