How to configure Web Api 2 to look for Controllers in a separate project? (just like I used to do in Web Api)

Question

I used to place my controllers into a separate Class Library project in Mvc Web Api. I used to add the following line in my web api project\'s global.asax to look for contro

Answer 1

It should work as is. Checklist

• Inherit ApiController
• End controller name with Controller. E.g. ValuesController
• Make sure WebApi project and class library project reference same WebApi assemblies
• Try to force routes using attribute routing
• Clean the solution, manually remove bin folders and rebuild
• Delete Temporary ASP.NET Files folders. WebApi and MVC cache controller lookup result
• Call `config.MapHttpAttributeRoutes(); to ensure framework takes attribute routes into consideration
• Make sure that the method you are calling is made to handle correct HTTP Verb (if it is a GET web method, you can call via browser URL, if it is POST you have to otherwise craft a web request)

This controller:

[RoutePrefix("MyValues")]
public class AbcController : ApiController
{
    [HttpGet]
    [Route("Get")]
    public string Get()
    {
        return "Ok!";
    }
}

matches this url:

http://localhost/MyValues/Get (note there is no /api/ in route because it wasn't specified in RoutePrefix.

---

Controller lookup caching: This is default controller resolver. You will see in the source code that it caches lookup result.

/// 

/// Returns a list of controllers available for the application.
/// 
/// An  of controllers.
public override ICollection GetControllerTypes(IAssembliesResolver assembliesResolver)
{
    HttpControllerTypeCacheSerializer serializer = new HttpControllerTypeCacheSerializer();

    // First, try reading from the cache on disk
    List matchingTypes = ReadTypesFromCache(TypeCacheName, IsControllerTypePredicate, serializer);
    if (matchingTypes != null)
    {
        return matchingTypes;
    }
...
}