Web API routing not working properly (action names)

Question

I got the following code, and I can't get the action name to work or is something else wrong here? I want to create a custom search, where usually when you look for one object in an api you search for the id, but I would like to search for the weekday for instance, but it could really be anything.

DayController.cs :

[ActionName("Weekday")]
public IHttpActionResult GetDayWeek(string q_day) {
    var day = controller.GetDay(q_day);
    if (day == null) {
        return NotFound();
    }
    return Ok(day);
}

Controller.cs :

public Day GetDay(string q_day) {
    var day = dal.GetDayByWeekday(q_day);
    return day;
}

Dal.cs :

public Day GetDayByWeekday(string q_day) {
    var day = db.Day.Where(d = > d.Weekday == q_day).Single();
    return day;
}

WebApiConfig.cs :

public static void Register(HttpConfiguration config) {
    config.MapHttpAttributeRoutes();

    config.Routes.MapHttpRoute(
    name: "DefaultApi",
    routeTemplate: "api/{controller}/{action}/{id}",
    defaults: new {
        id = RouteParameter.Optional
    });
}

Error:

<Error>
    <Message>
No HTTP resource was found that matches the request URI 'http://localhost:2096/api/Day/Weekday/monday'.
</Message>
    <MessageDetail>
No action was found on the controller 'Day' that matches the request.
</MessageDetail>
</Error>

Answer 1

Changing this:

[ActionName("Weekday")]
public IHttpActionResult GetDayWeek(string q_day) {
    var day = controller.GetDay(q_day);
    if (day == null) {
        return NotFound();
    }
    return Ok(day);
}

To this:

[Route("api/day/weekday/{q_day}")]
public IHttpActionResult GetDayWeek(string q_day) {
    var day = controller.GetDay(q_day);
    if (day == null) {
        return NotFound();
    }
    return Ok(day);
}

Did the trick in my testing

Some credit goes to JLevett for making me look at the Route-attribute

To explain:

The Route-attribute overrides the path to the method you're trying to call. Therefore it needs to be a full path with parameter names in it.

Do you have a method with multiple parameters this should work:

[Route("api/day/weekday/{q_day}/{w_day}")]
public IHttpActionResult GetDayWeekAndMore(string q_day, string w_day) {
...