C＃ 主窗按鈕的權限控制

//子表單啟動或關閉事件
       this.MdiChildActivate += new EventHandler(FMzMain_MdiChildActivate);

 private void FMzMain_MdiChildActivate(object sender, EventArgs e)
        {
            //判斷是否有子窗體並且是否是當前窗體（當關閉時，當前窗體為空）
            if (this.MdiChildren.Length > 0 && this.ActiveMdiChild != null)
            {
                CheckButtonOperateEnable();
            }
            else
            {
                CheckButtonOperateDisalbe();
            }
        }

        /// <summary>
        /// 開啟排列視窗按鈕
        /// scott 20070829
        /// </summary>
        public void CheckButtonOperateEnable()
        {
            //啟用排列視窗 scott 20070829
            tsmArrangeWdw.Enabled = true;
        }
        /// <summary>
        /// 關閉排列視窗按鈕
        /// scott 20070829
        /// </summary>
        public void CheckButtonOperateDisalbe()
        {
            //禁用排列視窗 scott 20070829
            tsmArrangeWdw.Enabled = false;       
        }