http://samueleresca.net/2014/11/web-api-sample/

webAPIsample\CharacterController.cs

//CharacterController.cs
public class CharacterController : ApiController
{

public IEnumerable GetCharacters()
{
return DataRepository.Characters;
}

public IEnumerabl GetCharacter(int characterId)
{
return DataRepository.Characters.Where(
cus => cus.TelefilmId == characterId);
}

public IEnumerable GetCharacter(string lastName)
{
return DataRepository.Characters.Where(
cus => cus.LastName.ToLower().Contains(lastName.ToLower()));
}
}

//TelefilmController.cs
public class TelefilmController : ApiController
{

public IEnumerable GetTelefilms() {
return DataRepository.Telefilms;
}

public Telefilm GetTelefilm(int telefilmId)
{
Telefilm result = DataRepository.Telefilms.SingleOrDefault(
acc => acc.TelefilmId == telefilmId);
if (result == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
return result;
}

}