MEF and ASP.NET MVC
- by denis_n
I want to use MEF with asp.net mvc.
I wrote following controller factory:
public class MefControllerFactory : DefaultControllerFactory
{
private CompositionContainer _Container;
public MefControllerFactory(Assembly assembly)
{
_Container = new CompositionContainer(new AssemblyCatalog(assembly));
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType != null)
{
var controllers = _Container.GetExports<IController>();
var controllerExport = controllers.Where(x => x.Value.GetType() == controllerType).FirstOrDefault();
if (controllerExport == null)
{
return base.GetControllerInstance(requestContext, controllerType);
}
return controllerExport.Value;
}
else
{
throw new HttpException((Int32)HttpStatusCode.NotFound,
String.Format(
"The controller for path '{0}' could not be found or it does not implement IController.",
requestContext.HttpContext.Request.Path
)
);
}
}
}
In Global.asax.cs I'm setting my controller factory:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterRoutes(RouteTable.Routes);
ControllerBuilder.Current.SetControllerFactory(new MefControllerFactory.MefControllerFactory(Assembly.GetExecutingAssembly()));
}
I have an area:
[Export(typeof(IController))]
[PartCreationPolicy(CreationPolicy.NonShared)]
public class HomeController : Controller
{
private readonly IArticleService _articleService;
[ImportingConstructor]
public HomeController(IArticleService articleService)
{
_articleService = articleService;
}
//
// GET: /Articles/Home/
public ActionResult Index()
{
Article article = _articleService.GetById(55);
return View(article);
}
}
IArticleService is an interface.
There is a class which implements IArticleService and Exports it.
It works.
Is this everything what I need for working with MEF?
How can I skip setting PartCreationPolicy and ImportingConstructor for controller?
I want to set my dependencies using constructor.
When PartCreationPolicy is missing, I get following exception:
A single instance of controller 'MvcApplication4.Areas.Articles.Controllers.HomeController' cannot be used to handle multiple requests. If a custom controller factory is in use, make sure that it creates a new instance of the controller for each request.
