ASP.NET Core 中 IoC 服务容器上下文中的请求是什么？

Question

What are the requests in the context of an IoC services container in ASP.NET Core?

I am learning the ASP.NET Core with the help of these tutorials. And I come across the following excerpt:

Scoped: IoC container will create an instance of the specified service type once per request and will be shared in a single request.

I can not grasp what request are we talking about here? Does it mean that every time a request is handled by a back end controller a new instance of the service provided by the IoC container will be created and implicitly placed in a class`s (which represents a controller) field? Or does it mean other kinds of requests?

In other words if we have:

public void ConfigureServices(IServiceCollection services)
{
    services.Add(new ServiceDescriptor(typeof(ILog), typeof(MyConsoleLogger), ServiceLifetime.Scoped));
}

public class HomeController : Controller
{
    ILog _log;

    public HomeController(ILog log)
    {
        _log = log;
    }
    public IActionResult Index()
    {
        _log.info("Executing /home/index");

        return View();
    }
}

will we have a different instance of the ILog in the _log every time a request is handled by the HomeController controller?

Answer 1

Yes, a new object will be created for each HTTP request. This can be useful for stateful dependencies that aren't thread-safe. Entity Framework object contexts are infamously required to be treated in this way.

If the dependency is stateless, or thread-safe, you can configure it with another lifetime so that only a single object is created and reused for the lifetime of the application.

Controllers like the above HomeController are always created per request . IIRC, you can't change that.