First try StructureMap and MVC3 via NuGet

Question

I'm trying to figure how to config StructureMap for ASP.NET MVC3 I've already using NuGet and I notice that it creates App_Start Folder with a cs file named as StructuremapMVC, so I check it and notice that is the same code but simplified that will be written manually on App_Start section placed on Global.asax...

This is my code from IoC Class

public static class IoC
    {
        public static IContainer Initialize()
        {
            ObjectFactory.Initialize(x =>
                        {
                            x.Scan(scan =>
                                    {
                                        scan.TheCallingAssembly();
                                        scan.WithDefaultConventions();
                                        scan.AddAllTypesOf<IController>();
                                    });
                            x.For<OpcionDB>().Use(() => new DatabaseFactory().Get());
                        });
            return ObjectFactory.Container;
        }
    }

My Question is Why I get an Exception when I inject some IoC on my Controllers as the follow (I use this pattern : Entity Framework 4 CTP 4 / CTP 5 Generic Repository Pattern and Unit Testable) :

        private readonly IAsambleaRepository _aRep;
        private readonly IUnitOfWork _uOw;

        public AsambleaController(IAsambleaRepository aRep, IUnitOfWork uOw)
        {
            _aRep = aRep;
            this._uOw = uOw;
        }

        public ActionResult List(string period)
        {
            var rs = _aRep.ByPeriodo(period).ToList<Asamblea>();

            return View();
        }

Exception showed :

Exception Details: System.MissingMethodException: No parameterless constructor defined for this object.

Answer 1

To handle parameters in the controller's constructor, the dependency resolver must be configured.

Check the following post on how to wire up the StructureMap with ASP.NET MVC3:

http://stevesmithblog.com/blog/how-do-i-use-structuremap-with-asp-net-mvc-3/

http://codebetter.com/jeremymiller/2011/01/23/if-you-are-using-structuremap-with-mvc3-please-read-this/

Answer 2

You are getting that error because you haven't setup StructureMap to resolve the dependencies needed to contruct the AsambleaController so it tries to find a parameterless constructor which there isn't one.

So what you need to do is setup StructureMap for IAsambleaRepository and IUnitOfWork.

On a side note, I'd say that IUnitOfWork should be a dependency on your repository and not your controller... your controller shouldn't need to know about the unit of work.