架构师训练营第二周课后作业

using Autofac;
using Autofac.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection;
namespace Samples.API
{
    public class Startup
    {
        public virtual IServiceProvider ConfigureServices(IServiceCollection services)
        {
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            var container = new ContainerBuilder();
            container.Populate(services);
            return new AutofacServiceProvider(container.Build());
        }
    }
}

using System;
using Microsoft.AspNetCore.Http;
namespace Samples.Services
{
    public class IdentityService
    {
        private IHttpContextAccessor _context;
        public IdentityService(IHttpContextAccessor context)
        {
            _context = context ?? throw new ArgumentNullException(nameof(context));
        }
        public string GetUserIdentity()
        {
            return _context.HttpContext.User.FindFirst("sub").Value;
        }
    }
}