Autofac Integration

Autofac is one of the most used dependency injection frameworks for .NET. It provides advanced features compared to .Net Core's standard DI library, like dynamic proxying and property injection.

Install Autofac Integration

All the startup templates and samples are Autofac integrated. So, most of the time you don't need to manually install this package.

Install Volo.Abp.Autofac nuget package to your project (for a multi-projects application, it's suggested to add to the executable/web project).

Install-Package Volo.Abp.Autofac

Then add AbpAutofacModule dependency to your module:

using Volo.Abp.Modularity;
using Volo.Abp.Autofac;

namespace MyCompany.MyProject
{
    [DependsOn(typeof(AbpAutofacModule))]
    public class MyModule : AbpModule
    {
        //...
    }
}

Finally, configure AbpApplicationCreationOptions to replace default dependency injection services by Autofac. It depends on the application type.

ASP.NET Core Application

Call UseAutofac() in the Program.cs file as shown below:

public class Program
{
    public static int Main(string[] args)
    {
        CreateHostBuilder(args).Build().Run();
    }

    internal static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            })
            .UseAutofac(); //Integrate Autofac!
}

If you are using the static WebApplication class, you can call the UseAutofac() extension method as shown below:

public class Program
{
    public async static Task Main(string[] args)
    {
        var builder = WebApplication.CreateBuilder(args);
        builder.Host.UseAutofac(); // Integrate Autofac!
        await builder.AddApplicationAsync<MyProjectNameWebModule>();
        var app = builder.Build();
        await app.InitializeApplicationAsync();
        await app.RunAsync();
    }
}

Console Application

Call UseAutofac() method in the AbpApplicationFactory.Create options as shown below:

using System;
using Microsoft.Extensions.DependencyInjection;
using Volo.Abp;

namespace AbpConsoleDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var application = AbpApplicationFactory.Create<AppModule>(options =>
            {
                options.UseAutofac(); //Autofac integration
            }))
            {
                //...
            }
        }
    }
}

Using the Autofac Registration API

If you want to use Autofac's advanced registration API, you need to access the ContainerBuilder object. Volo.Abp.Autofac nuget package defines the IServiceCollection.GetContainerBuilder() extension method to obtain the ContainerBuilder object.

Example: Get the ContainerBuilder object in the ConfigureServices method of your module class

public override void ConfigureServices(ServiceConfigurationContext context)
{
    var containerBuilder = context.Services.GetContainerBuilder();
    containerBuilder.RegisterType<MyService>(); // Using Autofac's registration API
}

You should install the Volo.Abp.Autofac nuget package to the project that you want to use the Autofac API.