Get a list of all registered objects implementing a certain interface

Question

Consider the following

builder.Register(c => new A());
builder.Register(c => new B());
builder.Register(c => new C());

B and C are both ISomeInterface.

I would now like to get an IEnumerable of all registered objects that implement ISomeInterface.

How can I accomplish this in Autofac?

Answer 1

Just tried this, works and does not depend on lifetime context:

Enumerate types using Activator instead

var types = con.ComponentRegistry.Registrations
     .Where(r => typeof(ISomeInterface).IsAssignableFrom(r.Activator.LimitType))
     .Select(r => r.Activator.LimitType);

Then to resolve:

IEnumerable<ISomeInterface> lst = types.Select(t => con.Resolve(t) as ISomeInterface);

Answer 2

If you have

container.Register(c => new A()).As<ISomeInterface>();
container.Register(c => new B()).As<ISomeInterface>();

Then when you do

var classes = container.Resolve<IEnumerable<ISomeInterface>>();

You will get a variable that is a list of ISomeInterface, containing A and B

Answer 3

Here is how I did it.

var l = Container.ComponentRegistry.Registrations
          .SelectMany(x => x.Services)
          .OfType<IServiceWithType>()
          .Where(x => 
                 x.ServiceType.GetInterface(typeof(ISomeInterface).Name) != null)
          .Select(c => (ISomeInterface) c.ServiceType);