How to create the class instances dynamically and call the implementation

I have various interfaces and I need to be able to call them. Here is the base class:

public class MyActorBase<TChild>: ActorBase where TChild : MyActorBase<TChild>
{
    public MyActorBase()
    {
       var actors =  ChildClass
           .GetInterfaces()
           .Where(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IActorMessageHandler<>))
           .Select(x=> (arguments: x.GetGenericArguments(), definition: x))
           .ToImmutableList();

       if (actors.Any())
       {
           var ty = actors.First();
           var obj = Activator.CreateInstance(ty.definition, true);

           // how to call method implementation
       }

    }

    protected sealed override bool Receive(object message) => false;
    private Type ChildClass => ((this as TChild)?? new object()).GetType();
}


public interface IActorMessageHandler<in T>
{
    Task Handle(T msg);
}

I read these blog post:

The writers already knew the type at compile time hence were able to cast correctly. I do not know anything at compile time so I cannot use a generic method or typecast it using () operator or as operator.

UPDATE: I think people are not getting the idea of what I want to achieve. so consider this. I made a nuget package which anyone can depend upon. Somewhere in the world, someone writes this code:

    public class MyMessage
    {
        public int Number { get; }

        public MyMessage(int number) => Number = number;
    }

    public class MyNewActor: MyActorBase<MyNewActor>, IActorMessageHandler<MyMessage>
    {
        public Task Handle(MyMessage msg)
        {
            return Task.CompletedTask;
        }
    }

I want that any class that implements the IActorMessageHandler, i should be able to call its method Handle(T msg). so while I was able to instantiate it (considering that I'm not using any dependency injection) how can I call the method in the most efficient way?

Is there any alternate to reflection?

Solution

you should not use Activator.CreateInstance it's very much expensive. instead, you may use Expression.Lamda to create objects in an efficient way.

  var object =  Expression.Lambda<Func<IActorMessageHandler<TChild>>>(Expression.New(ty.definition.Value.GetConstructor(Type.EmptyTypes) ?? throw new 
    Exception("Failed to create object"))
                        ).Compile()();