public static String Submit(String methodName){    string postData = "this is post data";//请求的数据，后面转换成二进制请求    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(new Uri(URL));    request.Method = "POST";    request.ContentType = "application/x-www-form-urlencoded";    request.Timeout = 60000;//一分钟    request.ReadWriteTimeout = 60000;//一分钟    request.KeepAlive = false;    byte[] datas = Encoding.UTF8.GetBytes(postData);    request.ContentLength = datas.Length;    Stream requestStream = request.GetRequestStream();    requestStream.Write(datas, 0, datas.Length);    requestStream.Close();    HttpWebResponse response = null;    string responseDatas = string.Empty;    try    {        //多线程中调用 HttpWebRequest 时，需要设置 ServicePointManager.DefaultConnectionLimit 数(默认连接数是 2)。         //当多线程请求时，同时的连接数超过Limit时，GetResponse会抛出 Timeout WebException。        ServicePointManager.DefaultConnectionLimit = 100;        response = (HttpWebResponse)request.GetResponse();        Stream streamResponse = response.GetResponseStream();        if (streamResponse != null)        {            using (StreamReader sr = new StreamReader(streamResponse))            {                responseDatas = sr.ReadToEnd();            }        }        else        {            responseDatas = "{\"Code\":-1,\"Data\":\"[]\"}";        }    }    finally    {        if (response != null)        {            try            {                response.Close();            }            catch            {                request.Abort();            }        }    }        return responseDatas;}

 request.ContentType = "application/x-www-form-urlencoded";这句话很重要，服务器的不同接收方式这里一定要标注准确了