302重定向，MVC中的Get，Post请求。

1.在访问页遇到重定向，Get，Post跳转处理，在跳转后的页面获取访问端的IP，他们的IP是否发生变化。。。

2.重定向处理后获取的IP还是访问端IP，而用Get，Post请求处理后，获取的访问端IP则是处理页的IP。

3.获取客户端IP的代码

   public string GetClientIP()
        {
            HttpContext current = HttpContext.Current;
            string userHostAddress = string.Empty;
            if (current != null)
            {
                if ((current.Session != null) && (current.Session["cnki_sys_user_remote_addr"] != null))
                {
                    userHostAddress = current.Session["cnki_sys_user_remote_addr"].ToString();
                    if (!string.IsNullOrEmpty(userHostAddress))
                    {
                        return userHostAddress;
                    }
                }
                userHostAddress = "127.0.0.1";
                userHostAddress = current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
                if (string.IsNullOrEmpty(userHostAddress))
                {
                    userHostAddress = current.Request.ServerVariables["REMOTE_ADDR"];
                    if (string.IsNullOrEmpty(userHostAddress))
                    {
                        userHostAddress = current.Request.UserHostAddress;
                    }
                }
                else
                {
                    string[] strArray = userHostAddress.Split(new char[] { ',' });
                    if ((strArray.Length > 1) && !string.IsNullOrEmpty(strArray[strArray.Length - 1]))
                    {
                        userHostAddress = strArray[strArray.Length - 1];
                    }
                }
                if (current.Session != null)
                {
                    current.Session["cnki_sys_user_remote_addr"] = userHostAddress;
                }
            }
            return userHostAddress;
        }

4.向mvcapi中发出的Post和Get请求，以及返回信息的接收和处理代码。

 public class ECPManage
    {
        public Result GetResultFromConfig(string config, params string[] para)//config是mvcapi的处理路径，para是参数。
        {
            string getUidUrl = string.Format(ConfigurationManager.AppSettings[config], para);
            string retJSON = SendGet(getUidUrl).TrimStart("?(".ToCharArray()).TrimEnd(')');
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream(System.Text.Encoding.UTF8.GetBytes(retJSON)))
            {
                System.Runtime.Serialization.Json.DataContractJsonSerializer serializer = new System.Runtime.Serialization.Json.DataContractJsonSerializer(typeof(Result));
                Result t = (Result)serializer.ReadObject(ms);
                return t;
            }
        }
        /// <summary>
        /// 发送post请求，返回信息
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="data"></param>
        /// <param name="encoding"></param>
        /// <returns></returns>
        public string SendPost(string uri, string data, string encoding = "utf8")
        {
            using (WebClient wCient = new WebClient())
            {
                if ("utf8" == encoding)
                {
                    wCient.Encoding = Encoding.UTF8;
                }
                else
                {
                    wCient.Encoding = Encoding.Default;
                }
                return wCient.UploadString(uri, data);
            }
        }
        /// <summary>
        /// 发送get请求，返回信息
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="encoding"></param>
        /// <returns></returns>
        public string SendGet(string uri, string encoding = "utf8")
        {
            using (WebClient wCient = new WebClient())
            {
                if ("utf8" == encoding)
                {
                    wCient.Encoding = Encoding.UTF8;
                }
                else
                {
                    wCient.Encoding = Encoding.Default;
                }
                return wCient.DownloadString(uri);
            }
        }
    }