Why does autofac delete an object before the end of HttpRequest?

Question

I am writing an ASP.NET MVC website using autofac for dependency injection, and Mindscape Lightspeed as ORM. There is a UserRepository class, which depends on LightSted UnitOfWork and which serves the Logon controller.

Problem . The UnitOfWork utility is removed before the UserRepository completes its use.

  public class UserRepository : IUserRepository
  {
    private readonly BluechipModelUnitOfWork _unitOfWork;

    public UserRepository(BluechipModelUnitOfWork unitOfWork)
    {
        _unitOfWork = unitOfWork;
    }
    public Principal GetPrincipal(string name)
    {
        // This line throws an ObjectDisposedException - UnitOfWork is already disposed.
        return _unitOfWork.Principals.FirstOrDefault(p => p.Name == name);
    }
    ...

In Global.asax, dependency postings are performed as follows:

public class MvcApplication : HttpApplication, IContainerProviderAccessor
{
    private static void RegisterAutofac()
    {
        var builder = new ContainerBuilder();

        // Register the lightspeed context as a singleton
        builder.RegisterInstance(new LightSpeedContext<BluechipModelUnitOfWork>("LightSpeedBluechip"))
            .As<LightSpeedContext<BluechipModelUnitOfWork>>()
            .SingleInstance();

        // Register the unit of work constructor so that a new instance is bound to each HttpRequest
        builder.Register(c => c.Resolve<LightSpeedContext<BluechipModelUnitOfWork>>().CreateUnitOfWork())
            .As<BluechipModelUnitOfWork>()
            .InstancePerLifetimeScope();

        // Register user repository to be one instance per HttpRequest lifetime
        builder.Register(c => new UserRepository(c.Resolve<BluechipModelUnitOfWork>()))
            .As<IUserRepository>()
            .InstancePerLifetimeScope();

        builder.Register(c => new CurrentUserService(
                                  c.Resolve<HttpSessionState>(),
                                  c.Resolve<IUserRepository>(),
                                  c.Resolve<IMembershipService>())
            ).As<ICurrentUserService>()
            .CacheInSession();

        builder.RegisterType<ExtensibleActionInvoker>().As<IActionInvoker>();
        builder.RegisterControllers(Assembly.GetExecutingAssembly()).PropertiesAutowired().InjectActionInvoker();
        builder.RegisterModelBinders(Assembly.GetExecutingAssembly());

        // Set the container provider up with registrations.    
        _containerProvider = new ContainerProvider(builder.Build());

        // Set the controller factory using the container provider.    
        ControllerBuilder.Current.SetControllerFactory(new AutofacControllerFactory(_containerProvider));

Given the above registrations, why autofac will recycle UnitOfWork (

Answer 1

- , ... CurrentUserService, :

    builder.Register(c => new CurrentUserService(
                                  c.Resolve<HttpSessionState>(),
                                  c.Resolve<IUserRepository>(),
                                  c.Resolve<IMembershipService>())
            ).As<ICurrentUserService>()
            .CacheInSession();

CacheInSession(), CurrentUserService IUserRepository, autofac, .

, , :

, , , . :

        builder.Register(c => new CurrentUserService(
                                  c.Resolve<HttpSessionState>(),
                                  c.Resolve<IUserRepository>(),
                                  c.Resolve<IMembershipService>())
            ).As<ICurrentUserService>()
            .InstancePerLifetimeScope();

...., CurrentUserService - , .