How to Specifying that a Parameter is Optional in MVC Attribute Routing? | ASP.Net MVC Interview Question

, ,
  • You can do it by Specifying that a parameter is Optional (via the '?' modifier).
  • This should be done after inline constraints.
  • Well,it's like this  [Route("Pet/{message:maxlength(4)?}")]
              
        PetController.cs

        // eg: /Pet/good
        [Route("Pet/{message:maxlength(4)?}")]
        public ActionResult PetMessage(string message)
        {
            return View();
        }

Key points of the above code
  • In the above example, /Pet/good and /Pet will Route to the “PetMessage” Action.
  • The route /Pet also works hence of the Optional modifier.
  • But /Pet/good-bye will not route above Action , because of the maxlength(4) constraint.

Above Routes on Browser are as below

parameter is Optional