treeview树形菜单的手动创建

 private void 添加节点ToolStripMenuItem_Click(object sender, EventArgs e)

        {

            TreeNode tn = new TreeNode();

            if (flag)

            {

                this.treeView1.SelectedNode.Nodes.Add(tn);

                this.treeView1.SelectedNode = tn;

                tn.BeginEdit();

                flag = false;

            }

            else

            {

                this.treeView1.Nodes.Add(tn);

                this.treeView1.SelectedNode = tn;

                tn.BeginEdit();

                flag = false;

            }

        }