private void DGUserEdit()        {            if(DGUser.SelectedItem!=null)            {                DataRow dr = (DGUser.SelectedItem as DataRowView).Row;                Page.UserEdit UE = new UserEdit(UserGrade, dr["UserName"].ToString());//声明子窗体                UE.Closed += new EventHandler(UE_Closed);//注册关闭事件                UE.ShowDialog();                            }        }        //在子窗体的关闭里写要刷新的内容，我这是重写绑定        private void UE_Closed(object sender,EventArgs e)        {            Band();        }