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);      }    }  }