//根據按+或- 來改變數量 public ActionResult CountCart(int?addpdid, int?lesspdid) { var user = int.Parse(Session["m_id"].ToString()); int add = Convert.ToInt32(addpdid); int less = Convert.ToInt32(lesspdid); if (add != 0) { _repo.CountCartQuantity(add, user, 1); } else { _repo.CountCartQuantity(less, user, -1); } return(RedirectToAction("Cart")); }