js 判断客户端 和 asp.net/C#判断客户端类型

    <script language="JavaScript">
  <!--
        onload = function browserRedirect() {
            //平台、设备和操作系统
            var system = {
                win: false,
                mac: false,
                xll: false,
                iphone: false
            };
            //检测平台
            var p = navigator.platform;
            system.iphone = p.indexOf("iPhone") == 0;
            system.win = p.indexOf("Win") == 0;
            system.mac = p.indexOf("Mac") == 0;
            system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);
            //跳转语句
            if (system.iphone) {
                alert("iPhone访问");
            } else if (system.win || system.mac || system.xll) {
                alert("PC访问");
            } else {
                alert("非PC访问");
            }
        };
  //-->
  </script>

  string str_u = Request.ServerVariables["HTTP_USER_AGENT"];

       
            if (str_u.ToLower().IndexOf("windows") > 0)
            {
                Response.Write("PC访问<br>");
            }
            if (str_u.ToLower().IndexOf("iphone") > 0)
            {
                Response.Write("iPhone访问<br>");
            }
            if (str_u.ToLower().IndexOf("android") > 0)
            {
                Response.Write("android访问<br>");
            }