/// <summary>
/// 判断手机用户UserAgent
/// </summary>
/// <returns></returns>
private bool IsMobile()
{
  HttpContext context = HttpContext.Current;
  if (context != null)
  {
    HttpRequest request = context.Request;
    if (request.Browser.IsMobileDevice)
      return true;
    string MobileUserAgent=System.Configuration.ConfigurationManager.AppSettings["MobileUserAgent"];
    Regex MOBILE_REGEX = new Regex(MobileUserAgent);
    if (string.IsNullOrEmpty(request.UserAgent) || MOBILE_REGEX.IsMatch(request.UserAgent.ToLower()))
      return true;
  }
  return false;
}

<script>
var system ={  win : false,  mac : false,  xll : false  };
//检测平台
var p = navigator.platform;
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.win||system.mac||system.xll)
{
  alert(system.mac)
}
else
{
  window.location.href="手机访问地址";
}
</script>