ASP.NET MVC routing: with querystring to one action, without to another

Question

I need the following routes:

example.com/products
goes to a product categories page (e.g. cars, trucks, buses, bikes)
controller=Products

Answer 1

Introduce Parameters. ASP.NET MVC allows you to create 'pretty' URLs, and that's exactly what you should do here:

First, the route mappings:

routes.MapRoute(
    "SpecificProducts",
    "products/{a}/{b}",
    new { controller = "products", action = "Categories" }
    );

routes.MapRoute(
    "ProductsIndex",
    "products".
    new { controller = "products", action = "Index" }
    );

Then, the controller actions

public ActionResult Index()
{
}

public ActionResult Categories(string a, string b) //parameters must match route values
{
}

This will allow you to use a search-friendly URL and you don't have to worry about query string parameters.