1.退款需要退款证书。C#都是用p12的证书，双击证书导入，密码是mch_id（商户号）
2.调用微信退款接口进行退款操作
1 string resp=string.Empty 2 string cert = Server.MapPath("apiclient_cert.p12"); 3 string password = mch_id;（商户号） 4 ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult); 5 6 //这两句特别注意 7 8 // X509Certificate cer = new X509Certificate(cert, password);//线下发布需要添加的 9 X509Certificate2 cer = new X509Certificate2(cert, password, X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.MachineKeySet);//线上发 布需要添加 10 11 HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(url); 12 webrequest.ClientCertificates.Add(cer); 13 webrequest.Method = "post"; 14 webrequest.ContentType = "application/x-www-form-urlencoded"; 15 webrequest.ContentLength = xml.Length; 16 HttpWebResponse response = null; 17 try 18 { 19 StreamWriter swRequestWriter = new StreamWriter(webrequest.GetRequestStream()); 20 swRequestWriter.Write(xml); 21 22 if (swRequestWriter != null) 23 swRequestWriter.Close(); 24 25 response = (HttpWebResponse)webrequest.GetResponse(); 26 using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.Default)) 27 { 28 resp = reader.ReadToEnd(); 29 } 30 } 31 catch (Exception exp) 32 { 33 throw exp; 34 } 35 finally 36 { 37 if (response != null) 38 response.Close(); 39 }
分享几个退款时遇到的问题
1、退款提示:订单号非法
原因：退款的订单号错误导致的
2、退款时提示：基础连接已关闭，或被意外关闭（验证证书的问题）
原因： 首先要通过证书请求退款的接口，其次要把下面的这行语句
// X509Certificate cer = new X509Certificate(cert, password);//线下发布需要添加的
修改成这样的才可以X509Certificate2 cer = new X509Certificate2(cert, password, X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.MachineKeySet);//线上发 布需要添加
3、 Miss Parameters
原因：传参数时，参数的名字和文档大小写不一致
4、每次退款，退款的订单号不能相同，否则无法退款
