Autofac register type with constructor

Question

I have class:

public class FunctionExtender : IFunctionsExtender
{
  private static IOptions<Settings> _settings;       
  private static ILogger<FunctionExtender> _logger;

  public FunctionExtender(IOptions<Settings> settings, ILogger<FunctionExtender> logger)
  {
    _settings = settings;
    _logger = logger;
  }
}

where IOptions is a Microsoft.Extensions.Options type and ILogger is a Microsoft.Extensions.Logging type. How can I register this type in Autofac container with it parameters? I tried something like that:

var container = new ContainerBuilder();
container.Populate(services);
container.RegisterType<FunctionExtender>()
                .WithParameter(new TypedParameter(typeof(IOptions<Settings>), ???));

but I don't know what to pass as second argument.

Answer 1

You just need to register FunctionExtender as IFunctionsExtender . Autofac will resolve the appropriate dependencies for you. It is one of the jobs of an inversion of control (IoC) container - register, resolve, release and dispose.

As of Autofac.Extensions.DependencyInjection Version 4.2.0 , here is all you need for ASP.Net Core 2 .

public class Startup
{
   public void ConfigureServices(IServiceCollection services)
   {
      ...
      services.AddMvc();
      ...
   }

   public void ConfigureContainer(ContainerBuilder builder)
   {
      builder.RegisterType<FunctionExtender>().As<IFunctionsExtender>();
   }
}

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .ConfigureServices(services => services.AddAutofac()) <======
            .UseStartup<Startup>()
            .Build();
}