AutoFacSamples/AutofacSamples3/Program.cs

using Autofac;
using System;
using System.Reflection;

namespace AutofacSamples3
{

    public interface ILog
    {
        void Write(string message);
    }

    public class ConsoleLog : ILog
    {
        public void Write(string message)
        {
            Console.WriteLine(message);
        }
    }

    public class EmailLog : ILog
    {
        private const string adminEmail = "tfoman@oeman.se";
        public void Write(string message)
        {
            Console.WriteLine($"Email sent to {adminEmail} : {message}");
        }
    }

    public class Engine
    {
        private ILog log;
        private int id;

        public Engine(ILog log, int id)
        {
            this.log = log;
            this.id = id;
        }

        public Engine(ILog log)
        {
            this.log = log;
            id = new Random().Next();
        }

        public void Ahead(int power)
        {
            log.Write($"Engine [{id}] ahead {power}");
        }
    }

    public class SMSLog : ILog
    {
        private readonly string phoneNumber;

        public SMSLog(string phoneNumber)
        {
            this.phoneNumber = phoneNumber;
        }
        public void Write(string message)
        {
            Console.WriteLine($"SMS to {phoneNumber} : {message}");
        }
    }

    public class Car
    {
        private Engine engine;
        private ILog log;

        public Car(Engine engine)
        {
            this.engine = engine;
            this.log = new EmailLog();
        }

        public Car(Engine engine, ILog log)
        {
            this.engine = engine;
            this.log = log;
        }

        public void Go()
        {
            engine.Ahead(100);
            log.Write("Car going forward...");
        }
    }

    public class Parent
    {
        public override string ToString()
        {
            return "I am your father";
        }
    }

    public class Child
    {
        public string Name { get; set; }
        public Parent Parent { get; set; }

        public void SetParent(Parent parent)
        {
            Parent = parent;
        }
    }

    public class ParentChildModule : Autofac.Module
    {
        protected override void Load(ContainerBuilder builder)
        {
            builder.RegisterType<Parent>();
            builder.Register(c => new Child() { Parent = c.Resolve<Parent>() });
        }
    }


    internal class Program
    {
        public static void Main(string[] args)
        {
            var builder = new ContainerBuilder();
            //builder.RegisterAssemblyModules(typeof(Program).Assembly);
            builder.RegisterAssemblyModules<ParentChildModule>(typeof(Program).Assembly);

            var container = builder.Build();
            Console.WriteLine(container.Resolve<Child>().Parent);

        }
    }
}