Web Api Controller in other project, route attribute not working

Question

I have a solution with two projects. One Web Api bootstap project and the other is a class library.

The class library contains a ApiController with attribute routing. I add a reference from web api project to the class library and expect this to just work.

The routing in the web api is configured:

config.MapHttpAttributeRoutes();

The controller is simple and looks like:

public class AlertApiController:ApiController
{
    [Route("alert")]
    [HttpGet]
    public HttpResponseMessage GetAlert()
    {
        return Request.CreateResponse<string>(HttpStatusCode.OK,  "alert");
    }
}

But I get a 404 when going to the url "/alert".

What am I missing here? Why can't I use this controller? The assembly is definitely loaded so I don't think http://www.strathweb.com/2012/06/using-controllers-from-an-external-assembly-in-asp-net-web-api/ is the answer here.

Any ideas?

Answer 1

Try this. Create a class in your class library project that looks like this,

public static class MyApiConfig {


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

And wherever you are currently calling the config.MapHttpAttributeRoutes(), instead call MyApiConfig.Register(config).

Answer 2

One possibility is you have 2 routes on different controllers with the same name.

I had 2 controllers both named "UploadController", each in a different namespace and each decorated with a different [RoutePrefix()]. When I tried to access either route I got a 404.

It started working when I changed the name of one of the controllers. It seems the Route Attribute is only keyed on the class name and ignores the namespace.