微信退款（在.net core 用http方式請求）

微信JSAPI支付  申請退款

介面地址

介面鏈接：https://api.mch.weixin.qq.com/secapi/pay/refund

是否需要證書

請求需要雙向證書。 詳見證書使用

請求參數

  public string GetWxGZHPayRefund(){
            //構造請求參數
            RequestHandler packageReqHandler = new RequestHandler();

            #region 構造請求參數
            packageReqHandler.SetParameter("appid", WxPayConfig.appid);//APPID
            packageReqHandler.SetParameter("mch_id", WxPayConfig.mchid);//商戶號
            packageReqHandler.SetParameter("nonce_str", TenPayV3Util.GetNoncestr());//隨機串
            packageReqHandler.SetParameter("out_refund_no", out_refund_no);
            packageReqHandler.SetParameter("out_trade_no", out_trade_no);//訂單號
            packageReqHandler.SetParameter("refund_fee", (int)(Convert.ToDecimal(refund_fee) * 100) + "");
            packageReqHandler.SetParameter("total_fee", (int)(Convert.ToDecimal(total_fee) * 100) + ""); //金額,以分為單位
            packageReqHandler.SetParameter("transaction_id", transaction_id);
            packageReqHandler.SetParameter("sign", packageReqHandler.CreateMd5Sign("key", WxPayConfig.key));//商戶API密鑰（簽名） 
                                                                                                            //
        
            #endregion

            //將參數轉為xml字元串
            string data = packageReqHandler.ParseXML(); //發起post非同步請求，獲取返回的內容
      
      
            //本地或者伺服器的證書位置（證書在微信支付申請成功發來的通知郵件中）
            string cert = @"D:\WSHH\apiclient_cert.p12";

            //私鑰（在安裝證書時設置）
            string password = WxPayConfig.mchid;

            ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
            //調用證書
            X509Certificate2 cer = new X509Certificate2(cert, password, X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.MachineKeySet);

            #region 發起post請求
            HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(WxPayConfig.refund_url);
            webrequest.ClientCertificates.Add(cer);
            webrequest.Method = "post";

            byte[] postdatabyte = Encoding.UTF8.GetBytes(data);
            webrequest.ContentLength = postdatabyte.Length;
            Stream stream;
            stream = webrequest.GetRequestStream();
            stream.Write(postdatabyte, 0, postdatabyte.Length);
            stream.Close();

            HttpWebResponse httpWebResponse = (HttpWebResponse)webrequest.GetResponse();
            StreamReader streamReader = new StreamReader(httpWebResponse.GetResponseStream());
            string responseContent = streamReader.ReadToEnd();
            #endregion

            var res = System.Xml.Linq.XDocument.Parse(responseContent);
            string return_code = res.Element("xml").Element("return_code").Value;

            Hashtable hashtable = new Hashtable();

            hashtable.Add("return_code", return_code);

            return dicResult;

        }
        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
            if (errors == SslPolicyErrors.None)
                return true;
            return false;
        }

註意：

  如果報：基本賬戶餘額不足，請充值後重新發起   ，那就是基本賬戶餘額不足， 充個一塊錢就好了