public ActionResult Lists(int?act, int?type, int?id, string value) { switch (act) { case 1: if (type != null) { db_man.AddRefItem((int)type); } break; case 2: if (id != null) { db_man.DelRefItemById((int)id); } break; case 3: if (id != null && value != null) { db_man.UpdateRefItem((int)id, value); } break; } return(View(db_man.ReferenseBook)); }