在依赖解析Unity上获取HttpContext.Current

Question

如何在UnityConfig中获取HttpContext.Current？在应用程序启动时结果为null。我需要在依赖关系解析时获得应用程序的当前URL。这是我的代码

public static void RegisterTypes(IUnityContainer container)
      {
        // NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
        // container.LoadConfiguration();
        //this is null
        var http = HttpContext.Current;
        container
            //add additional constructor to support the HostHelper of current set up
           .RegisterType<IDataContextAsync, OEPDataContext>(new PerRequestLifetimeManager(), new InjectionConstructor(HostHelper.GetConfiguration()))
           .RegisterType<IUnitOfWorkAsync, UnitOfWork>(new PerRequestLifetimeManager())
           .RegisterType<IRepositoryAsync<Menu>, Repository<Menu>>()
           .RegisterType<IMenuService, MenuService>();
        // TODO: Register your types here
        // container.RegisterType<IProductRepository, ProductRepository>();
    }