C# get post 的方法

#region GET POST

        /// <summary>
        /// Get String data = GetString(URL , "PKEY=" + Pkeylist);
        /// </summary>
        /// <param name="URL"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static string GetString(string URL, string parameters)
        {
            Stream instream = null;
            StreamReader sr = null;
            HttpWebResponse response = null;
            HttpWebRequest request = null;
            Encoding encoding = Encoding.UTF8;
            // 准备请求...
            try
            {
                // 设置参数
                request = WebRequest.Create(URL +"?"+ parameters) as HttpWebRequest;
                CookieContainer cookieContainer = new CookieContainer();
                request.CookieContainer = cookieContainer;
                request.AllowAutoRedirect = true;
                request.Method = "GET";
                request.ContentType = "application/x-www-form-urlencoded";

                //发送请求并获取相应回应数据
                response = request.GetResponse() as HttpWebResponse;
                instream = response.GetResponseStream();
                sr = new StreamReader(instream, encoding);
                //返回结果网页（html）代码
                string content = sr.ReadToEnd();
                string err = string.Empty;
                return content.Trim();
            }
            catch (Exception ex)
            {
                string err = ex.Message;
                return err;
            }
        }
        /// <summary>
        /// POST string data = PostString(URL , "PKEY=" + Pkeylist);
        /// </summary>
        /// <param name="URL"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static string PostString(string URL, string parameters)
        {
            Stream outstream = null;
            Stream instream = null;
            StreamReader sr = null;
            HttpWebResponse response = null;
            HttpWebRequest request = null;
            Encoding encoding = Encoding.UTF8;
            byte[] data = encoding.GetBytes(parameters);
            // 准备请求...
            try
            {
                // 设置参数
                request = WebRequest.Create(URL) as HttpWebRequest;
                CookieContainer cookieContainer = new CookieContainer();
                request.CookieContainer = cookieContainer;
                request.AllowAutoRedirect = true;
                request.Method = "POST";
                request.ContentType = "application/x-www-form-urlencoded";
                request.ContentLength = data.Length;
                outstream = request.GetRequestStream();
                outstream.Write(data, , data.Length);
                outstream.Close();
                //发送请求并获取相应回应数据
                response = request.GetResponse() as HttpWebResponse;
                //直到request.GetResponse()程序才开始向目标网页发送Post请求
                instream = response.GetResponseStream();
                sr = new StreamReader(instream, encoding);
                //返回结果网页（html）代码
                string content = sr.ReadToEnd();
                string err = string.Empty;
                return content.Trim();
            }
            catch (Exception ex)
            {
                string err = ex.Message;
                return err;
            }
        }

 #endregion