.NET Core 微信小程序退款步骤——（统一退款）

services.AddSenparcGlobalServices(Configuration)
.AddSenparcWeixinServices(Configuration);
IRegisterService register = RegisterService.Start(env, senparcSetting.Value).UseSenparcGlobal(false, null);
register.UseSenparcWeixin(senparcWeixinSetting.Value, senparcSetting.Value)
 .RegisterTenpayV3(senparcWeixinSetting.Value, "appid"); 

publicbool RefundProduct(OrdOrderProduct ordOrderProduct, PayOrderMstParam payOrderMstParam, OrdOrderPayItem ordOrderPayItem, string appID, DateTime thisTime, ref string errMsg)
{
 try
 {
 OrdOrderPayMst refPay = null;
 if (!PayOrderManager.CreatePayOrderMST(payOrderMstParam, thisTime, ref refPay, ref errMsg))
 {
  errMsg = "生成退款单出错!" + errMsg;
  return false;
 }
 var PayInfo = Senparc.Weixin.Config.SenparcWeixinSetting.Items[appID];
 string AppID = PayInfo.WxOpenAppId;
 string AppSecret = PayInfo.WxOpenAppSecret;
 string Mch_id = PayInfo.TenPayV3_MchId;//商户号
 string Mch_key = PayInfo.TenPayV3_Key;//商户密钥
 string notifyUrl = string.Format(PayInfo.TenPayV3_TenpayNotify, "RefundNotifyUrl");
 var timeStamp = TenPayV3Util.GetTimestamp();
 var nonceStr = TenPayV3Util.GetNoncestr();
 //支付源单号
 string outTradeNo = ordOrderPayItem.PayNo;//商户订单号/支付单号
 refPay.PayNoSource = ordOrderPayItem.PayNo;
 //退款单号
 string outRefundNo = refPay.PayNo;//新退款单号
 //支付时的总金额
 int totalFee = (int)(ordOrderPayItem.PayPrice * 100);
 //退款金额
 int refundFee = (int)(refPay.PayPrice * 100);
 string opUserId = PayInfo.TenPayV3_MchId;
 var dataInfo = new TenPayV3RefundRequestData(AppID, Mch_id, Mch_key,
  null, nonceStr, null, outTradeNo, outRefundNo, totalFee, refundFee, opUserId, null, notifyUrl: notifyUrl);
 //Logger.Info($"PayInfo={PayInfo.SerializeObject()}");
 //Logger.Info($"dataInfo={dataInfo.SerializeObject()}");
 //var basePath = AppContext.BaseDirectory;
 //var certPath = Path.Combine(basePath, "Config/apiclient_cert.p12");
 //var cert = @"D:\projects\orderapi.trydou.com\Config\apiclient_cert.p12";//根据自己的证书位置修改
 //var password = Mch_id;//默认为商户号，建议修改
 //配置好证书地址，V3自动识别
 var result = TenPayV3.Refund(dataInfo);
 refPay.PayResult = result.SerializeObject();
 //Logger.Info("提交退款申请：" + refPay.PayResult);
 if (result.return_code.ToUpper() == "SUCCESS" && result.result_code.ToUpper() == "SUCCESS")
 {
  using (TransactionScope scope = new TransactionScope(TransactionScopeAsyncFlowOption.Enabled))
  {
  //业务处理
  //提交事务
  scope.Complete();
  }
  return true;
 }
 else
 {
  errMsg = result.err_code_des;
  Logger.Error(string.Format("提交退款失败，退款单号={0},关联订单号={1},关联产品={2},退款result={3}",
  refPay.PayNo, refPay.RelationNo, refPay.RelationNos, refPay.PayResult));
 }
 }
 catch (Exception ex)
 {
 errMsg = ex.Message;
 Logger.Error(string.Format("提交退款异常：Message={0}，StackTrace={1}", ex.Message, ex.StackTrace));
  }
  return false;
 }

/// <summary>
/// 退款回调
/// </summary>
[HttpPost("RefundNotifyUrl")]
public ActionResult RefundNotifyUrl()
{
 ResponseResult result = new ResponseResult();
 ResponseHandler resHandler = new ResponseHandler(HttpContext);
 string return_code = resHandler.GetParameter("return_code");
 string return_msg = resHandler.GetParameter("return_msg");
 try
 {
 var mch_key = Senparc.Weixin.Config.SenparcWeixinSetting.TenPayV3_Key;
 if (return_code.ToUpper() == "SUCCESS")
 {
  //string result_code = resHandler.GetParameter("result_code");
  //string appId = resHandler.GetParameter("appid");
  //string mch_id = resHandler.GetParameter("mch_id");
  //string nonce_str = resHandler.GetParameter("nonce_str");
  string req_info = resHandler.GetParameter("req_info");
  var decodeReqInfo = TenPayV3Util.DecodeRefundReqInfo(req_info, mch_key);
  var decodeDoc = XDocument.Parse(decodeReqInfo);
  var refundNotifyXml = decodeDoc.SerializeObject();
  //获取接口中需要用到的信息
  string out_trade_no = decodeDoc.Root.Element("out_trade_no").Value;
  string out_refund_no = decodeDoc.Root.Element("out_refund_no").Value;
  string transaction_id = decodeDoc.Root.Element("transaction_id").Value;
  string refund_id = decodeDoc.Root.Element("refund_id").Value;
  int total_fee = int.Parse(decodeDoc.Root.Element("total_fee").Value);
  int refund_fee = int.Parse(decodeDoc.Root.Element("refund_fee").Value);
  RefundNotifyParam param = new RefundNotifyParam()
  {
  PayNo = out_trade_no,//商户订单号
  PayPrice = ((float)refund_fee.ToInt() / 100).ToDecimal(),//退款金额
  Out_refund_no = out_refund_no,//商户退款单号 
  TransactionNo = transaction_id,//微信订单号
  Refund_id = refund_id, //微信退款单号 
  };
  Logger.Info(string.Format("退款回调参数，return_code={0},return_msg={1},refundNotifyXml={2}", return_code, return_msg, refundNotifyXml));
  result = Service.RefundNotifyUrl(param);
  if (result.errno != 0)
  {
  //回调处理逻辑失败
  Logger.Error(string.Format("退款回调业务处理失败：退款单号{0}，{1}", param.Out_refund_no, result.errmsg));
  }
  else
  {
  Logger.Info(string.Format("退款回调业务处理成功,退款单号：{0}", param.Out_refund_no));
  string xml = string.Format(@"<xml>
    <return_code><![CDATA[{0}]]></return_code>
    <return_msg><![CDATA[{1}]]></return_msg>
    </xml>", return_code, return_msg);
  return Content(xml, "text/xml");
  }
 }
 else
 {
  //错误的订单处理
  Logger.Error(string.Format("退款回调失败，return_code={0},return_msg={1}", return_code, return_msg));
 }
 }
 catch (Exception ex)
 {
 Logger.Error(string.Format("退款回调异常：Message={0}，StackTrace={1}", ex.Message, ex.StackTrace));
 }
 return Content("fail", "text/xml");
}