protected void Application_BeginRequest() { var lang = ""; var userLanguages = Request.UserLanguages;
if (userLanguages != null && userLanguages.Length > 0)
{
    lang = userLanguages[0].ToLowerInvariant();
}
switch (lang)
{
    case "zh-cn":
        Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo("zh-CN");
        Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo("zh-CN");
        break;
    case "zh-tw":
        Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo("zh-TW");
        Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo("zh-TW");
        break;
    default:
        Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
        Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
        break;
}
}
public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapMvcAttributeRoutes();
routes.MapRoute(
    name: "Default",
    url: "{language}/{controller}/{action}/{id}",
    defaults: new { language = "zh-cn", controller = "Home", action = "Index", id = UrlParameter.Optional },
    constraints: new { language = "(en|zh-cn|zh-tw)" }
);
routes.MapRoute(
    name: "Default_en",
    url: "en/{controller}/{action}/{id}",
    defaults: new { language = "en", controller = "Home", action = "Index", id = UrlParameter.Optional }
);
routes.MapRoute(
    name: "Default_cn",
    url: "zh-cn/{controller}/{action}/{id}",
    defaults: new { language = "zh-cn", controller = "Home", action = "Index", id = UrlParameter.Optional }
);
routes.MapRoute(
    name: "Default_tw",
    url: "zh-tw/{controller}/{action}/{id}",
    defaults: new { language = "zh-tw", controller = "Home", action = "Index", id = UrlParameter.Optional }
);
}