Asp.net获取客户端真实IP,非代理地址

 public string GetUserIP()
   {
       string _userIP;
       if(Request.ServerVariables["HTTP_VIA"] == null)
         {
             userIP= Request.UserHostAddress;
         }
       else
        {
           userIP= Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
        }
       return userIP;

    }

也可以写成下面这样

 public string GetUserIP()
   {
       if(Request.ServerVariables["HTTP_VIA"] == null)
         {
            string userIP= Request.UserHostAddress;
            return userIP;
         }
       else
        {
           string userIP= Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
           return userIP;
        }
    }