Resolve instance - Autofac

Question

I'm trying to figure out how to resolve a instance somewhere in the code.

At the application startup I registered a type

static void Main()
{    
    var builder = new ContainerBuilder();
    builder.RegisterType<Foo>().As<IFoo>();
}

Now, how can I resolve an instance somewhere in the code ?

In StructureMAP there is a static object ObjectFactory.GetInstance<IFoo>()

Answer 1

Read up on Getting Started. It should get you started.

First off, what you are looking for is the container. Build it from the ContainerBuilder like in this simple WinForms app:

static void Main()
{
    using (var container = builder.Build())
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);

        var mainForm = container.Resolve<MainForm>();
        Application.Run(mainForm)
    }
}

The general idea is that you only have to resolve the first or topmost instance. The container will handle creating all other instances based on dependency injection through constructor parameters.

If the DI pattern is followed throughout your application you should only have to touch the container once at startup.

How you resolve the topmost instance depends largely on what type of application you are building. If its a web app, the ASP.Net integration and MVC integration will take care of it for you. (After all, the topmost instance in ASP.Net is the Application which is out of our control).

On the other hand, if its a console app or WinForms app you would resolve the first instance manually in Main, like my sample above.