public string GetPrepayId(string operater, string trade_type, string openid, string orderSn, decimal orderAmount, string goods_tag, string ip, string body, DateTime?time_expire = null)
        {
            CustomJsonResult result = new CustomJsonResult();


            TenpayUtil tenpayUtil = new TenpayUtil(wxConfig);

            UnifiedOrder unifiedOrder = new UnifiedOrder();

            unifiedOrder.openid           = openid;
            unifiedOrder.out_trade_no     = orderSn;                            //商户订单号
            unifiedOrder.spbill_create_ip = ip;                                 //终端IP
            unifiedOrder.total_fee        = Convert.ToInt32(orderAmount * 100); //标价金额
            unifiedOrder.body             = body;                               //商品描述
            unifiedOrder.trade_type       = trade_type;
            if (time_expire != null)
            {
                unifiedOrder.time_expire = time_expire.Value.ToString("yyyyMMddHHmmss");
            }

            if (!string.IsNullOrEmpty(goods_tag))
            {
                unifiedOrder.goods_tag = goods_tag;
            }

            string prepayId = tenpayUtil.GetPrepayId(unifiedOrder);

            //using (TransactionScope ts = new TransactionScope())
            //{

            //    result = new CustomJsonResult(ResultType.Success, ResultCode.Success, "操作成功");
            //}

            return(prepayId);
        }