微信jsapi支付 退款接口

微信官方退款接口文档地址:https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_4

参数按照文档构造 记录出现错误:System.Net.WebException: The remote server returned an error: (400) Bad Request

这个是由于退款接口需要传证书

证书的话是需要登录商户号进行下载api证书 下载好导入到服务器中 调用支付接口的时候添加证书即可

public  string PostWebRequest(string postUrl, string paramData)
    {
        string ret = string.Empty;
        try
        {
　　　　　　
            byte[] byteArray = Encoding.Default.GetBytes(paramData); //转化
            HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(new Uri(postUrl));
            webReq.Method = "POST";
            webReq.ContentType = "application/x-www-form-urlencoded";
            webReq.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)";

　　　　　　　//初始化证书 fileName：证书存放的地址 password 证书的密码
            X509Certificate2 certificate = new X509Certificate2(fileName,password); 

　　　　　　　//添加证书
            webReq.ClientCertificates.Add(certificate);  



            webReq.ContentLength = byteArray.Length;
            Stream newStream = webReq.GetRequestStream();   //
            newStream.Write(byteArray, 0, byteArray.Length);//写入参数
            ServicePointManager.SecurityProtocol =  SecurityProtocolType.Tls | SecurityProtocolType.Ssl3;
            HttpWebResponse response = (HttpWebResponse)webReq.GetResponse();       //这里报错
            StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            ret = sr.ReadToEnd();
            newStream.Close();
            sr.Close();
            response.Close();
            newStream.Close();
        }
        catch (Exception ex)
        {
            return ex.Message;
        }
        return ret;

    }