public string Consumption(int id,double money,int gid,int uid) { YogaEntities ye = new YogaEntities(); Member cc = ye.Member.FirstOrDefault((ccc) => ccc.Id == id); if (cc == null) return string.Format("编号为{0}的会员不存在", id); if (cc.CardRestMoney < money) return "余额不足"; Goods g = ye.Goods.FirstOrDefault((gg) => gg.Id == gid); if (g == null) return string.Format("编号为{0}的商品不存在", gid); User u = ye.User.FirstOrDefault((uu) => uu.Id == uid); if (u == null) return string.Format("编号为{0}的操作员不存在", uid); cc.CardRestMoney -= money; cc.Score += (int)money; var cr = new ConsumptionRecord() { Date = DateTime.Now, MemberId = id, MemberName = cc.Name, GoodsId = gid, GoodsName = g.Name, UserId = uid, Operater = u.Name }; ye.AddToConsumptionRecord(cr); return ye.SaveChanges() == 2 ? "扣值成功" : "扣值失败"; }