<system.webServer>
    <modules runAllManagedModulesForAllRequests="true" />
  </system.webServer>

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}.html",
                defaults: new { controller = "Home", action = "Index" }
            );

home/index.html?page=1

home/index/1.html  (这种写法无法自定义参数名称，只能使用路由里配置的参数名称)

        public ActionResult Welcome(int? page)
        {
            ViewBag.Message = "第"+page+"页";
            return View();
        }

        public ActionResult Welcome(int page=1)
        {
            ViewBag.Message = "第"+page+"页";
            return View();
        }