Multiple actions were found that match the request Web API?

Question

I am using web API and i am new in this. I am stuck in a routing problem. I have a controller with following actions :

    // GET api/Ceremony
    public IEn         


        

Answer 1

The problem here is your 2 Get methods will resolve to api/Ceremony and MVC does not allow parameter overloading. A quick workaround (not necessarily the preferred approach) for this sort of problem is to make your id parameter nullable e.g.

// GET api/Ceremony
public IEnumerable GetCeremonies(int? id)
{
    if (id.HasValue)
    {
        Ceremony ceremony = db.Ceremonies.Find(id);
        return ceremony;
    }
    else
    {
        return db.Ceremonies.AsEnumerable();
    }
}

However, you would then be returning a list of ceremonies when with 1 item when your trying to query for a single ceremony - if you could live with that then it may be the solution for you.

The recommended solution is to map your paths appropriately to the correct actions e.g.

context.Routes.MapHttpRoute(
    name: "GetAllCeremonies",
    routeTemplate: "api/{controller}",
    defaults: new { action = "GetCeremonies" }
);

context.Routes.MapHttpRoute(
    name: "GetSingleCeremony",
    routeTemplate: "api/{controller}/{id}",
    defaults: new { action = "GetCeremony", id = UrlParameter.Optional }
);