How to get current User outside a Controller in Web API .NET Core

Question

I'm trying to get the current User from the Context outside a controller in my Web API. I'm using the OpenIddict to authenticate users, so the authorization is made by tokens.

I have registered the HttpContextAcessor as a singleton in my Startup.cs:

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

After that, I inject the HttpContexrAcessor in my hub, like this:

public class NotificationHub : Hub
    {
        private IHttpContextAccessor _contextAccessor;
        private HttpContext _context { get { return _contextAccessor.HttpContext; } }

        public NotificationHub(IHttpContextAccessor contextAccessor)
        {
            _contextAccessor = contextAccessor;
        }

        public async Task JoinGroup()
        {
            Groups.Add(Context.ConnectionId, $"notification_{_context.User.Identity.Name}");
        }

        public void Send(JsonResult notification)
        {
                Clients.Client(Context.ConnectionId).sendNotification(notification);
        }
    }

The problem is that _context.User.Identity.Name is always null.

Is there some way to do that?

Answer 1

In my case using .Net Core 2.0, where I needed to get the User Id outside the controller, in Application Service, I did the following:

in Startup.cs I added this line under ConfigureServices

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

I created the following class

public class UserResolverService
{
    private readonly IHttpContextAccessor _httpContext;
    private readonly UserManager<ApplicationUser> _userManager;

    public UserResolverService(IHttpContextAccessor httpContext, UserManager<ApplicationUser> userManager)
    {
        _httpContext = httpContext;
        _userManager = userManager;
    }

    public string GetUserId()
    {
        var userId = _userManager.GetUserId(_httpContext.HttpContext.User);
        return userId;
    }
}

In my Application Service class, I called the UserResolverService

public class MyApplicationService
{
    private readonly ApplicationDbContext _context;
    private readonly UserResolverService _userResolverService;

    public MyApplicationService(ApplicationDbContext context, UserResolverService userResolverService)
    {
        _context = context;
        _userResolverService = userResolverService;
    }

    public async Task Create(MyModel entity)
    {
        entity.CreatorUserId = _userResolverService.GetUserId();
        _context.MyModel.Add(entity);
        await _context.SaveChangesAsync();
    }
}

Also, if you don't want to user the UserManager, you can simply make the UserResolverService class like this:

public class UserResolverService
{
    private readonly IHttpContextAccessor _httpContext;

    public UserResolverService(IHttpContextAccessor httpContext)
    {
        _httpContext = httpContext;
    }
    public string GetUserId()
    {
        var user = _httpContext?.HttpContext?.User as ClaimsPrincipal;
        var userId = user.Claims.ElementAt(0).Value;
        return userId;
    }
}

Answer 2

Try this: https://msdn.microsoft.com/pt-br/library/system.threading.thread.currentprincipal(v=vs.110).aspx

System.Threading.Thread.CurrentPrincipal