TreeView实现双击修改树结点名称

        private Point pi;//定义一个坐标变量
        //TreeRule为TreeView的Name
        private void TreeRule_MouseDown(object sender, MouseEventArgs e)//当鼠标指针位于控件上并按下鼠标键时发生
        {
            pi = new Point(e.X, e.Y);//记录当前位置
        }

        private void TreeRule_DoubleClick(object sender, EventArgs e)
        {
            TreeNode node = this.TreeRule.GetNodeAt(pi);//检索位于指定点的树节点
            if (pi.X >= node.Bounds.Left && pi.X <= node.Bounds.Right)//当鼠标双击的位置在某个结点上时
            {
                editMenuTree.LabelEdit = true;//开启树结点的标签文本编辑状态
                if (!TreeRule.SelectedNode.IsEditing)
                {
                    TreeRule.SelectedNode.BeginEdit();//使该结点进入编辑状态
                }
            }
        }

        private void TreeRule_AfterLabelEdit(object sender, NodeLabelEditEventArgs e)//编辑状态结束时触发
        {
            if(e.Label != null)
            {
                if (e.Label.Trim().Length > 0)//输入的值不为空
                {
                    string sql = string.Format("update region set menuname = '{0}' where id = {1}",e.Label.Trim(),Convert.ToInt32(e.Node.Name));//进行更新操作
                    if (db.ExecuteSql(sql) != 1)//执行sql语句失败
                    {
                        e.CancelEdit = true;//取消当前编辑，恢复到最初状态
                    }

                    TreeNodeName = e.Label.Trim();

                    TreeRule.SelectedNode.Text = TreeNodeName;

                }
                else
                {
                    e.CancelEdit = true;
                }
            }
            
        }