post请求

     public static String RequestUrl(String url, byte[] data, String method = "POST")
     {
         try
         {
 
             WebRequest request = WebRequest.Create(url);
             request.Method = method;
             request.ContentType = "application/x-www-form-urlencoded";
 
             if (data != null && data.Length > 0)
             {
                 request.ContentLength = data.Length;
                 Stream newStream = request.GetRequestStream();
                 newStream.Write(data, 0, data.Length);
                 newStream.Close();
             }
             else
             {
                 request.ContentLength = 0;
             }
 
 
             WebResponse response = request.GetResponse();
             Stream stream = response.GetResponseStream();
             MemoryStream ms = new MemoryStream();
             long ChunkSize = 1024;
             byte[] buffer = new byte[ChunkSize];
             long dataLengthToRead = response.ContentLength;//获取响应数据的总大小
             while (dataLengthToRead > 0)
             {
                 int lengthRead = stream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小
                 ms.Write(buffer, 0, lengthRead);
                 dataLengthToRead = dataLengthToRead - lengthRead;
             }
             stream.Close();
             response.Close();
 
             string responseText = Encoding.UTF8.GetString(ms.ToArray());
             return responseText;
 
         }
         catch (Exception ex)
         {
             return ex.Message;
         }
     }