Autofac Modules C# Tutorial

C# > Patterns > Dependency Injection  > Autofac Modules


Create a project with the following structure:

Project.cs

namespace AutofacModules

{

    public class Project

    {

        public int Id { get; set; }

        public string Name { get; set; }

    }

}

Task.cs

namespace AutofacModules

{

    public class Task

    {

        public int Id { get; set; }

        public string Name { get; set; }

    }

}

IProjectRepository.cs

namespace AutofacModules

{

    public interface IProjectRepository

    {

        void Create(Project project);

    }

}

ITaskRepository.cs

namespace AutofacModules

{

    public interface ITaskRepository

    {

        void Create(Task task);

    }

}

ProjectModule.cs

Register a component to be created through reflection.

using Autofac;

namespace AutofacModules

{

    public class ProjectModule : Module

    {

        protected override void Load(ContainerBuilder builder)

        {

            builder.RegisterType<ProjectRepository>().As<IProjectRepository>();

            base.Load(builder);

        }

    }

}

TaskModule.cs

using Autofac;

namespace AutofacModules

{

    public class TaskModule : Module

    {

        protected override void Load(ContainerBuilder builder)

        {

            builder.RegisterType<TaskRepository>().As<ITaskRepository>();

            base.Load(builder);

        }

    }

}

RegistrationModule.cs

Add a module to the container.

using Autofac;

namespace AutofacModules

{

    public class RegistrationModule

    {

        public static IContainer BuildContainer()

        {

            var builder = new ContainerBuilder();

            builder.RegisterModule<ProjectModule>();

            builder.RegisterModule<TaskModule>();

            return builder.Build();

        }

    }

}

Example:

            Project project = new Project()

            {

                Id = 1,

                Name = "Project 1"

            };

            Task task = new Task()

            {

                Id = 1,

                Name = "Task 1"

            };

            var container = RegistrationModule.BuildContainer();

//Retrieve a service from the context.

            var projectRepository = container.Resolve<IProjectRepository>();

            var taskRepository = container.Resolve<ITaskRepository>();

            projectRepository.Create(project);

            taskRepository.Create(task);

Dependency Injection in C# with Autofac - real world example

C# > Patterns > Dependency Injection  > Autofac

Autofac is an addictive Inversion of Control container for .NET 4.5, Silverlight 5, Windows Store apps, and Windows Phone 8 apps

Source: http://autofac.org/

Dependency Injection in C# with Autofac - real world example

using Autofac;

using System;

using System.Linq;

using System.Collections.Generic;

using System.Windows.Forms;

namespace WindowsFormsApplication4

{

    public class Programmer

    {

        public string Name { get; set; }

        public IList<string> Skills { get; set; }

    }

    public class Project

    {

        public string Name { get; set; }

        readonly IList<Programmer> _programmers;

        readonly IDispatcher _dispatcher;

        public Project(IList<Programmer> programmers, IDispatcher dispatcher)

        {

            _programmers = programmers;

            _dispatcher = dispatcher;

        }

        public void FindProgrammers()

        {

            var programmers = _programmers.Where(e => e.Skills.Contains("VB"));

            foreach (var p in programmers)

                _dispatcher.Notify(p);

        }

    }

    public interface IDispatcher

    {

        void Notify(Programmer programmer);

    }

    public class Email : IDispatcher

    {

        private readonly string _message;

        public Email(string message)

        {

            _message = message;

        }

        public void Notify(Programmer programmer)

        {

            Console.WriteLine("Sent message {0} to {1}", _message,  programmer.Name);

        }

    }

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            List<Programmer> lst = new List<Programmer>();

            Programmer p = new Programmer();

            p.Name = "Dan";

            p.Skills = new List<string>();

            p.Skills.Add("VB");

            lst.Add(p);

            Email email = new Email("Notification email message");

            ContainerBuilder autofac = new ContainerBuilder();

            autofac.Register(o => new Project(o.Resolve<IList<Programmer>>(), o.Resolve<IDispatcher>()));

            autofac.RegisterType<Email>().As<IDispatcher>();

            autofac.RegisterInstance(lst).As<IList<Programmer>>();

            autofac.RegisterInstance(email).As<IDispatcher>();

           

            using (var container = autofac.Build())

            {

                container.Resolve<Project>().FindProgrammers();

            }

        }

    }

}