gistfile1.cs

    /// <summary>
    /// Factory de controllers utilizada no lugar da padrão
    /// para usar o Unity pra resolver as dependências dos objetos
    /// </summary>
    public class UnityControllerFactory : DefaultControllerFactory
    {
        readonly IUnityContainer _container;

        public UnityControllerFactory(IUnityContainer container)
        {
            _container = container;
        }
        
        protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
        {
            if (controllerType == null)
                throw new ArgumentNullException("controllerType");

            if (!typeof(IController).IsAssignableFrom(controllerType))
                throw new ArgumentException(string.Format(
                    "Type requested is not a controller: {0}", controllerType.Name),
                    "controllerType");

            return _container.Resolve(controllerType) as IController;
        }
    }

    public interface IContainerAccessor
    {
        IUnityContainer Container { get; }
    }


    public class MvcApplication : System.Web.HttpApplication, IContainerAccessor
    {
        #region Injeção de dependência

        private static UnityContainer _container;

        public static IUnityContainer Container
        {
            get { return _container; }
        }

        IUnityContainer IContainerAccessor.Container
        {
            get { return Container; }
        }

        private static void InicializarDI()
        {
            if (_container == null)
                _container = new UnityContainer();

            RegistrarDependencias();

            IControllerFactory controllerFactory = new UnityControllerFactory(_container);

            ControllerBuilder.Current.SetControllerFactory(controllerFactory);

        }

        /// <summary>
        /// Registra no objeto do Unity as dependências dos objetos
        /// </summary>
        private static void RegistrarDependencias()
        {
            _container
                .RegisterType<IContaUsuarioService, ContaUsuarioService>()
                    .Configure<InjectedMembers>()
                        .ConfigureInjectionFor<UsuarioController>(new InjectionConstructor(typeof(IContaUsuarioService)));
            _container
                .RegisterType<IUsuarioRepository, UsuarioRepository>()
                    .Configure<InjectedMembers>()
                        .ConfigureInjectionFor<ContaUsuarioService>(new InjectionConstructor(typeof(IUsuarioRepository)));

        }

        #endregion

        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                "Default",                                              // Route name
                "{controller}/{action}/{id}",                           // URL with parameters
                new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
            );

        }

        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();

            RegisterRoutes(RouteTable.Routes);

            //Chama o Unity para registrar as dependências dos objetos
            InicializarDI();
        }
    }