微信小程序netcore后台api支付结果通知接口的坑

终于搞定回调通知了,这里总结下几个暗坑

1.回调通知一定是post接口,且可以直接访问

2.需要解析回调的HttpContext内容才能知道结果

3.收到信息一定要进行验证判断是否来自于微信渠道

4.回调信息要去重,防止重复接收

5.无论成功与否,都要给微信回复个标准模板,否则微信会一直给你发

因为封装entity很麻烦,所以直接用盛派的SDK,引用如下:

 

        /// <summary>
        /// 支付回调地址（在统一下单接口中设置notify_url）
        /// https://localhost:44373/api/WxPay/PayNotifyUrl
        /// 注意:回调必须是post
        /// </summary>
        /// <returns></returns>
        [HttpPost("PayNotifyUrl")]
        public ActionResult PayNotifyUrl()
        {
            try
            {
                var resHandler = new ResponseHandler(HttpContext);
                var return_code = resHandler.GetParameter("return_code");
                var return_msg = resHandler.GetParameter("return_msg");
                var openid = resHandler.GetParameter("openid");

                resHandler.SetKey(TenPayV3Info.ApiKey);
                //验证请求是否从微信发过来（安全）
                if (!resHandler.IsTenpaySign())
                {
                    // 验证不通过,支付失败
                    throw new Exception($"支付验证不通过:[{return_code}][{return_msg}][{openid}]");
                }
                var notify = new PaidNotify
                {
                    ResultCode = return_code,
                    ReturnMsg = return_msg,
                    Openid = openid,
                };
                if (return_code.ToUpper() == "SUCCESS")
                {
                    //直到这里，才能认为交易真正成功了，可以进行数据库操作，但是别忘了返回规定格式的消息！
                    notify.Appid = GetTxt(resHandler, "appid");
                    notify.MchId = GetTxt(resHandler, "mch_id");
                    notify.DeviceInfo = GetTxt(resHandler, "device_info");
                    notify.NonceStr = GetTxt(resHandler, "nonce_str");
                    notify.Sign = GetTxt(resHandler, "sign");
                    notify.SignType = GetTxt(resHandler, "sign_type");
                    notify.ResultCode = GetTxt(resHandler, "result_code");
                    notify.ErrCode = GetTxt(resHandler, "err_code");
                    notify.ErrCodeDes = GetTxt(resHandler, "err_code_des");
                    notify.Openid = GetTxt(resHandler, "openid");
                    notify.IsSubscribe = GetTxt(resHandler, "is_subscribe");
                    notify.TradeType = GetTxt(resHandler, "trade_type");
                    notify.BankType = GetTxt(resHandler, "bank_type");
                    notify.TotalFee = GetInt(resHandler, "total_fee");
                    notify.SettlementTotalFee = GetInt(resHandler, "settlement_total_fee");
                    notify.FeeType = GetTxt(resHandler, "fee_type");
                    notify.CashFee = GetInt(resHandler, "cash_fee");
                    notify.CashFeeType = GetTxt(resHandler, "cash_fee_type");
                    notify.CouponFee = GetInt(resHandler, "coupon_fee");
                    notify.CouponCount = GetInt(resHandler, "coupon_count");
                    notify.CouponTypeN = GetTxt(resHandler, "coupon_type_$n");
                    notify.CouponIdN = GetTxt(resHandler, "coupon_id_$n");
                    notify.CouponFeeN = GetInt(resHandler, "coupon_fee_$n");
                    notify.TransactionId = GetTxt(resHandler, "transaction_id");
                    notify.OutTradeNo = GetTxt(resHandler, "out_trade_no");
                    notify.Attach = GetTxt(resHandler, "attach");
                    notify.TimeEnd = GetTxt(resHandler, "time_end");
                }


                #region 发送支付成功的模板消息
                try
                {
                    var appId = TenPayV3Info.WebId;//与微信公众账号后台的AppId设置保持一致，区分大小写。
                    var templateData = new WeixinTemplate_PaySuccess(NotifyUrl, "购买商品", "状态：" + return_code);

                    SenparcTrace.SendCustomLog("支付成功模板消息参数", appId + " , " + openid);

                    //var result = AdvancedAPIs.TemplateApi.SendTemplateMessage(appId, openId, templateData);
                }
                catch (Exception ex)
                {
                    SenparcTrace.SendCustomLog("支付成功模板消息", ex.ToString());
                }
                #endregion

                // 添加支付结果记录
                //PaymentService.AddPaidNotify(notify);

                var xml = AppPay.PayNotifyXml(return_code, return_msg);
                return Content(xml, "text/xml");
            }
            catch (Exception ex)
            {
                var err = new WeixinException(ex.Message, ex);
                Log(err.Message);
                var xml = AppPay.PayNotifyXml("FAIL", ex.Message);
                return Content(xml, "text/xml");
            }
        }

        static int? GetInt(ResponseHandler handler, string key)
        {
            var txt = handler.GetParameter(key);
            return int.TryParse(txt, out var num) ? (int?)num : null;
        }

        static string GetTxt(ResponseHandler handler, string key)
        {
            return handler.GetParameter(key);
        }

        /// <summary>
        /// 日志记录
        /// </summary>
        /// <param name="msg"></param>
        static void Log(string msg)
        {
            var logDir = ServerUtility.ContentRootMapPath($"~/App_Data/PayNotifyUrl/{SystemTime.Now:yyyyMMdd}");
            if (!Directory.Exists(logDir))
            {
                Directory.CreateDirectory(logDir);
            }
            var logPath = Path.Combine(logDir, $"{SystemTime.Now:yyyyMMdd}-{SystemTime.Now:HHmmss}-{Guid.NewGuid().ToString("n").Substring(0, 8)}.txt");
            using (var fileStream = System.IO.File.OpenWrite(logPath))
            {
                fileStream.Write(Encoding.Default.GetBytes(msg), 0, Encoding.Default.GetByteCount(msg));
                fileStream.Close();
            }
        }

只有收到return_code="success"时才会有详细信息,成功后微信会把订单的详细结果发过来,如图:

最后,正确返回微信结果很重要,xml格式如下:

/// <summary>
        /// 收到财付通消息后返回的回调通知
        /// </summary>
        /// <param name="return_code"></param>
        /// <param name="return_msg"></param>
        /// <returns></returns>
        public static string PayNotifyXml(string return_code = "SUCCESS", string return_msg = "OK")
        {
            return [e-mail]"<xml><return_code><![CDATA[{return_code}]]></return_code><return_msg><![CDATA[{return_msg}]]></return_msg></xml>";
        }