今天上午研究了一下微信支付的接口,发现网上转的大部分都是从微信支付接口文档上copy下来的,并没有任何实际的代码,因此写了一个微信的支付接口测试的小程序。

调用微信支付接口其实主要需要两个部分,一个是需要证书,二是组织参数

1.证书,在微信商户中将证书下载到测试机,注意的是,如果用.NET的话,一定要双击下载的证书并安装,否则后期调试接口的时候会报错,错误为:CA证书出错,请登录微信支付商户平台下载证书;

2.组织参数的时候主要的就是签名的生成,其实只要按照接口文档的步骤,一个个写下来,是没有任何问题的,容易出错的是当参数有中文的时候,容易出现错误,错误为:签名错误


下面是我写的主要的代码,以一段段的函数呈现:

1.组织参数,以字典的结构存储参数:

public string Create()
         {
             Dictionary<string, string> nativeObj = new Dictionary<string, string>();
             nativeObj.Add("nonce_str", "3857F5B380EA425B91D4DD3D5F5A6594");
             nativeObj.Add("mch_id", "商户号");
             nativeObj.Add("mch_billno",“自己按照接口文档写的”);
             nativeObj.Add("wxappid", "微信公众平台id");
             nativeObj.Add("nick_name", "自定义");
             nativeObj.Add("send_name", "自定义");
             nativeObj.Add("re_openid", "用户的openid");
             nativeObj.Add("total_amount", "100");
             nativeObj.Add("min_value", "100");
             nativeObj.Add("max_value", "100");
             nativeObj.Add("total_num", "1");
             nativeObj.Add("wishing", "感谢您参加猜灯谜活动,祝您元宵节快乐!");
             nativeObj.Add("client_ip", "本机的ip地址");
             nativeObj.Add("act_name", "猜灯谜抢红包活动 ");
             nativeObj.Add("remark", "猜越多得越多,快来抢!");           //用来生成签名的方法,具体见下面
             string sign = GetSign(nativeObj);
             nativeObj.Add("sign", sign);         //将参数组织成xml形式的字符串
             return ToXml(nativeObj);
         }2.生成签名:
public string GetSign(Dictionary<string, string> nativeObj)
         {
             string sign = "";
             Dictionary<string, string> newobj = new Dictionary<string, string>();
             string temp = "";           //参数的排序及去空
             var dicSort = from objDic in nativeObj where objDic.Value != "" orderby objDic.Key select objDic;
             foreach (var item in dicSort)
             {
                 if (temp != "")
                     temp += "&";
                 temp += item.Key + "=" + item.Value;
             }
             temp += "&key=api密钥";           //MD5加密
             sign = StringToMD5(temp,32).ToUpper();
             return sign;
         } public  string StringToMD5(string str, int i)
         {
             //获取要加密的字段,并转化为Byte[]数组
             byte[] data = System.Text.Encoding.Unicode.GetBytes(str.ToCharArray());
             //建立加密服务
             System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
             //加密Byte[]数组
             byte[] result = md5.ComputeHash(data);
             //将加密后的数组转化为字段
             if (i == 16 && str != string.Empty)
             {
                 return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower().Substring(8, 16);
             }
             else if (i == 32 && str != string.Empty)
             {
                 return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower();
             }
             else
             {
                 switch (i)
                 {
                     case 16: return "000000000000000";
                     case 32: return "000000000000000000000000000000";
                     default: return "请确保调用函数时第二个参数为16或32";
                 }

             }
         }

3. 将参数组织成要提交的数据

public string ToXml(Dictionary<string, string> arr)
         {
             String xml = "<xml>";

             foreach (KeyValuePair<string, string> pair in arr)
             {
                 String key = pair.Key;
                 String val = pair.Value;
                 if (IsNumeric(val))
                 {
                     xml += "<" + key + ">" + val + "</" + key + ">";

                 }
                 else
                     xml += "<" + key + "><![CDATA[" + val + "]]></" + key + ">";
             }
             xml += "</xml>";
             return xml;
         }public bool IsNumeric(String str)
         {
             try
             {
                 int.Parse(str);
                 return true;
             }
             catch
             {
                 return false;
             }
         }


4.模拟post请求提交

public string Pay()
         {
             int dt = DateTime.Now.Millisecond;
             string url = "https://api.mch.weixin.qq.com/mmpaymkttransfers/sendredpack";
             string cert = @"D:\cert\apiclient_cert.p12";//这里是你存储证书的位置
             string password = "**********";//证书密码
             //这一段借鉴的是微信官方提供的DEMO
             ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
             X509Certificate cer = new X509Certificate(cert, password);
             HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(url);
             webrequest.ClientCertificates.Add(cer);
             webrequest.Method = "post";
             webrequest.ContentType = "text/xml";            //这一段是自己写的添加post数据的方法
             string postData = CreateNativePackage();
             StreamWriter myWriter = null;
             要注意的这是这个编码方式,还有内容的Xml内容的编码方式
             //Encoding encoding = Encoding.GetEncoding("UTF-8");
             try
             {
                 myWriter = new StreamWriter(webrequest.GetRequestStream());
                 myWriter.Write(postData);
             }
             catch (Exception e)
             {
             }
             finally
             {
                 myWriter.Close();
             }
             HttpWebResponse webreponse = (HttpWebResponse)webrequest.GetResponse();
             Stream stream = webreponse.GetResponseStream();
             string resp = string.Empty;
             using (StreamReader reader = new StreamReader(stream))
             {
                 resp = reader.ReadToEnd();
             }
             string msg = resp;              return msg;
         }private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
         {
             if (errors == SslPolicyErrors.None)
                 return true;
             return false;
         }