public ActionResult PageDetail(){  var thisList = _sysDepartmentBll.GetAllDepartmentList();//數據源  //添加一條默認數據  var resultList = new List<SelectListItem>  {    new SelectListItem {Text = "--請選擇--", Selected = true, Value = ""}  };  //將數據源添加到resultList集合中  resultList.AddRange(thisList.Select(thisModel => new SelectListItem  {    Text = thisModel.DepartmentName,    Selected = false,    Value = thisModel.DepartmentId  }));  ViewBag.DepartmentList= GetDepartmentSelectList(_sysDepartmentBll.GetAllDepartmentList());  return View();}