获取客户端IP地址 for ASP.NET

        /// <summary>
        /// 获取Ip地址
        /// </summary>
        /// <returns></returns>
        public static string GetIp()
        {
            string user_IP;
            if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
            {
                user_IP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
            }
            else
            {
                user_IP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();
            }
            return user_IP;
        }