/// <summary>
/// 获取客户端IP地址（无视代理）
public static string GetHostAddress()
     { 
         if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
             return System.Web.HttpContext.Current.Request
                 .ServerVariables["HTTP_X_FORWARDED_FOR"].Split(new char[] { ',' })[0];
         else
             return System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
     }

string ssIp = System.Web.HttpContext.Current.Request.UserHostAddress;
            IPHostEntry iph = Dns.GetHostByAddress(ssIp);
            Session["strPCName"] = iph.HostName;