If you are using ASP.NET MVC and you want to use DI (Dependency Injection) in your application you can create a custom controller factory.
Letās implement a custom controller factory that uses Unity as DI Container.
First we have to create a class named UnityControllerFactory. This class has to be derived from ASP.NET MVCās built-in DefaultControllerFactory. Next we have to override the GetControllerInstance method and return a control instance by using a unity container.
//Defines a custom control factory which uses unity to get a new controller instance.
public class UnityControllerFactory : DefaultControllerFactory
{
//Unity container instance.
private IUnityContainer _unityContainer;
//Creates a new instance of UnityControllerFactory.
public UnityControllerFactory(IUnityContainer unityContainer)
{
if (unityContainer == null)
{
throw new ArgumentException();
}
this._unityContainer = unityContainer;
}
//Retrieves a controller instance for the specified request context and controller type by using Unity.
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null)
{
return null;
}
return this._unityContainer.Resolve(controllerType) as IController;
}
}
Finally we have to assign a new instance of UnityControllerFactory asĀ controller factory of our applicationās ControllerBuilder.
UnityControllerFactory unityFactory = new UnityControllerFactory(new UnityContainer());
ControllerBuilder.Current.SetControllerFactory(unityFactory);
Below the implementation of our MVC application class.
//MVC Application
public class MvcApplication : System.Web.HttpApplication
{
//Registeres global filters.
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute());
}
//Registers routes.
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 = UrlParameter.Optional } // Parameter defaults
);
}
//Application startup method.
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
UnityControllerFactory unityFactory = new UnityControllerFactory(new UnityContainer());
ControllerBuilder.Current.SetControllerFactory(unityFactory);
}
}
Our Unity controller factory implementation is completed and you can enjoy it 
nicolagmt
dotnetslang 