asp.net c#获取访问者原始IP地址

但访问者访问站点时，经常需要获取客户的原始IP地址，比如用了Cloudflare，阿里CDN加速等云加速

这个时候，获取原始IP地址方法需要稍作处理

        /// <summary>
        /// 获得远程客户端IP
        /// </summary>
        /// <returns></returns>
        public static string SiteIP()
        {
            var request = System.Web.HttpContext.Current.Request;

            string ip = string.Empty;
            if (!string.IsNullOrEmpty(request["X_FORWARDED_FOR"]))
            {
                return SiteIPSplit(request["X_FORWARDED_FOR"]);
            }
            else if (request.ServerVariables["HTTP_VIA"] != null)
            {
                if (request.ServerVariables["HTTP_X_FORWARDED_FOR"] == null)
                {
                    if (request.ServerVariables["HTTP_CLIENT_IP"] != null)
                        ip = request.ServerVariables["HTTP_CLIENT_IP"].ToString();
                    else
                        if (request.ServerVariables["REMOTE_ADDR"] != null)
                        ip = request.ServerVariables["REMOTE_ADDR"].ToString();
                }
                else
                    ip = request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
            }
            else if (request.ServerVariables["REMOTE_ADDR"] != null) ip = request.ServerVariables["REMOTE_ADDR"].ToString();
            if (string.IsNullOrEmpty(ip)) ip = request.UserHostAddress;
            return ip;
        }

        public static string SiteIPSplit(string IP)
        {
            if (IP.IndexOf(",") != -1)
            {
                string[] ip = IP.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);
                return ip[0];
            }
            return IP;
        }