关于C#通过HttpWebRequest调用web api 接口post 传参的问题

 /// <summary>  

        /// 创建POST方式的HTTP请求  

        /// </summary>  

        /// <param name="url">请求的URL</param>  

        /// <param name="parameters">随同请求POST的参数名称及参数值字典</param>  

        /// <param name="timeout">请求的超时时间</param>  

        /// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>  

        /// <param name="requestEncoding">发送HTTP请求时所用的编码</param>  

        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>  

        /// <returns></returns>  

        public static HttpWebResponse CreatePostHttpResponse(string url, IDictionary<string, string> parameters, int? timeout, string userAgent, Encoding requestEncoding, CookieCollection cookies)

        {

            if (string.IsNullOrEmpty(url))

            {

                throw new ArgumentNullException("url");

            }

            if (requestEncoding == null)

            {

                throw new ArgumentNullException("requestEncoding");

            }

            HttpWebRequest request = null;

            //如果是发送HTTPS请求  

            if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))

            {

                ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);

                request = WebRequest.Create(url) as HttpWebRequest;

                request.ProtocolVersion = HttpVersion.Version10;

            }

            else

            {

                request = WebRequest.Create(url) as HttpWebRequest;

            }

            request.Method = "POST";

            

            request.Headers.Add("X_REG_CODE", "288a633ccc1");

            request.Headers.Add("X_MACHINE_ID", "a306b7c51254cfc5e22c7ac0702cdf87");

            request.Headers.Add("X_REG_SECRET", "de308301cf381bd4a37a184854035475d4c64946");

            request.Headers.Add("X_STORE", "0001");

            request.Headers.Add("X_BAY", "0001-01");

            request.Headers.Add("X-Requested-With", "XMLHttpRequest");

            request.ContentType = "application/x-www-form-urlencoded";

            request.Headers.Add("Accept-Language", "zh-CN");

            request.Headers.Add("Accept-Encoding", "gzip, deflate");

            request.Accept = "*/*";

            

            if (!string.IsNullOrEmpty(userAgent))

            {

                request.UserAgent = userAgent;

            }

            else

            {

                request.UserAgent = DefaultUserAgent;

            }



            if (timeout.HasValue)

            {

                request.Timeout = timeout.Value;

            }

           // if (cookies != null)

           // {

                request.CookieContainer = new CookieContainer();

               // request.CookieContainer.Add(cookies);

           // }

            //如果需要POST数据  

            if (!(parameters == null || parameters.Count == 0))

            {

                StringBuilder buffer = new StringBuilder();

                int i = 0;

                foreach (string key in parameters.Keys)

                {

                    if (i > 0)

                    {

                        buffer.AppendFormat("&{0}={1}", key, parameters[key]);

                    }

                    else

                    {

                        buffer.AppendFormat("{0}={1}", key, parameters[key]);

                    }

                    i++;

                }



                byte[] data = requestEncoding.GetBytes(buffer.ToString());

                using (Stream stream = request.GetRequestStream())

                {

                    stream.Write(data, 0, data.Length);

                }              

            }   

            HttpWebResponse res;

            try

            {

                res = (HttpWebResponse)request.GetResponse();

            }

            catch (WebException ex)

            {

                res = (HttpWebResponse)ex.Response;

            }



            return res;

        }

   public string GetCookies()

        {

           



            string url = "http://localhost:17766/Account/LogOn";



            IDictionary<string, string> parameters = new Dictionary<string, string>();

            parameters.Add("StoreCode", "0001");

            parameters.Add("UserName", "T00000");

            parameters.Add("Password", "123456");



            



            //string postData = "StoreCode=0001&UserName=T00000&Password=123456";



            //HttpWebResponseUtility.PostData(postData, url, null);







            Encoding encoding = Encoding.GetEncoding("gb2312"); 



            HttpWebResponse response = HttpWebResponseUtility.CreatePostHttpResponse(url, parameters, null, null, encoding, null);







            String xml = new StreamReader(response.GetResponseStream(), Encoding.UTF8).ReadToEnd();



            return xml;



        }