How to add robots.txt into ASP.NET MVC site?

There are two ways to do so:
First one:
http://rayaspnet.blogspot.ca/2011/04/how-to-implment-dynamic-robotstxt-in.html

Second, the simpler one:
Add robots.txt into your website root, and Add one line into Global.asax file

        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
            routes.IgnoreRoute("robots.txt");
        }