Why is Autofac needed?

Autofac is needed to manage dependencies in .NET applications efficiently. It provides a flexible and powerful inversion of control (IoC) container that handles the instantiation and lifetime of objects, allowing for easier maintenance, scalability, and testability of code.

What is Dependency injection?

Dependency injection is a design pattern in software development where the dependencies of a class are provided externally rather than created within the class itself. This will help in making the code more modular, flexible, and easier to test, as it decouples components and allows for easier swapping or modification of dependencies without changing the core logic of the code.

I have provided simple steps to set up Autofac dependency injection in ASP .NET Core 8.

Step 1: Install Autofac Packages:

• Use the NuGet Package Manager or .NET CLI to install Autofac and Autofac.Extensions.DependencyInjection.

Step 2: Configure Autofac Container:

• Inside the ConfigureServices method of your Startup.cs file, build the Autofac container, and set it as the service provider.

public IServiceProvider ConfigureServices(IServiceCollection services)
{
    var builder = new ContainerBuilder();
    builder.Populate(services);
    var container = builder.Build();
    return new AutofacServiceProvider(container);
}

Step 3: Define Services (Interfaces and Implementations):

• Define interfaces for services and their implementations separately for loose coupling and testability.

public interface IService1
{
    void DoSomething();
}

public class Service1: IService1
{
    public void DoSomething()
    {
        // You can implement service logic here
    }
}

Step 4: Register Services with Autofac:

• Create a method named ConfigureContainer in Startup.cs to register services with Autofac using a ContainerBuilder.

public void ConfigureContainer(ContainerBuilder builder)
{
    builder.RegisterType<Service1>().As<Service1>();
    // You have to register other services and dependencies here
}

Step 5: Use Services in Your Application:

• Use constructor injection to access registered services in controllers or other classes throughout the application.