Register all implementation of type T interface in .NET core

Question

I have an interface

public interface IEvent { }

An Event class

public class ContactEvent : IEvent { }

Two Event Handlers classes

public class ContactCreateHandler : IEventHandler<ContactEvent> { }
public class ContactUpdateHandler : IEventHandler<ContactEvent> { }

In .NET 4.5 this was possible using Autofac

var assemblies = BuildManager.GetReferencedAssemblies()
            .Cast<Assembly>()
            .ToArray()

builder.RegisterAssemblyTypes(assemblies)
.AsClosedTypesOf(typeof(IEventHandler<>)).AsImplementedInterfaces().InstancePerRequest();

And then I would get the list of classes based on the type T

var handlerList = _container.Resolve<IEnumerable<IEventHandler<T>>>();

How to do this in .NET Core

Answer 1

You could use Scrutor. With that, you can then scan and assign the handlers like this:

// Automatically discover and register all message handlers...
services.Scan(
    x =>
        {
            var entryAssembly = Assembly.GetEntryAssembly();
            var referencedAssemblies = entryAssembly.GetReferencedAssemblies().Select(Assembly.Load);
            var assemblies = new List<Assembly> { entryAssembly }.Concat(referencedAssemblies);

            x.FromAssemblies(assemblies)
                .AddClasses(classes => classes.AssignableTo(typeof(IEventHandler<>)))
                    .AsImplementedInterfaces()
                    .WithScopedLifetime();
        });