使用 AddHttpContextAccessor 在 ASP.NET Core 3.1 MVC 中获取当前登录的用户 ID

Question

I have a web app with user management, the main problem is that admins can delete themselves and thus crashing the application. I had the idea of getting the current user id registered so if the one that is currently logged tries to delete himself, it blocks that action.

The real problem resides in that I have no idea of what I'm doing wrong trying to get the under ID (a string)

I added services.AddHttpContextAccessor(); in the Startup class and added

private readonly IHttpContextAccessor _httpContextAccessor;

public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options, IHttpContextAccessor httpContextAccessor)
        : base(options)
{
        _options = options;
        _httpContextAccessor = httpContextAccessor;
}

in the applicationDbContext.

Finally on the class where the dealing user's method is, I created

private readonly IHttpContextAccessor _httpContextAccessor;

and then I tried to use this snippet of code:

var userId = _httpContextAccessor.HttpContext.User.FindFirst(ClaimTypes.NameIdentifier).Value;

but that returns null. The whole context of the method is as follows:

public async Task DeleteUsuarioAsync(String id)
{
        var strategy = _context.Database.CreateExecutionStrategy();
        await strategy.ExecuteAsync(async () => {
            using (var transaction = _context.Database.BeginTransaction())
            {
                try
                {
                    var user = _context.Users.Where(u => u.Id.Equals(id)).ToList().Last();
                    var _listRoles = await _userRole.getRole(_userManager, _roleManager, id);
                    await _userManager.RemoveFromRoleAsync(user, _listRoles[0].Text);
                    var dataUser = _context.TUsers.Where(u => u.IdUser.Equals(id)).ToList().Last();
                    var idUser = user.Id;
                    var userId = _httpContextAccessor.HttpContext.User.FindFirst(ClaimTypes.NameIdentifier).Value;

                    if (idUser != "25c986cb-d0d3-41aa-aae6-cfcd2279f458")
                    {
                        if (userId == idUser)
                        {
                        }
                        else
                        {
                            _context.Remove(dataUser);
                            _context.SaveChanges();
                            _context.Remove(user);
                            _context.SaveChanges();
                            transaction.Commit();
                        }
                    }
                    else
                    {
                    }

                    //if (idUser == "25c986cb-d0d3-41aa-aae6-cfcd2279f458")
                    //{
                    //}
                    //else
                    //{
                    //    _context.Remove(dataUser);
                    //    _context.SaveChanges();
                    //    _context.Remove(user);
                    //    _context.SaveChanges();
                    //    transaction.Commit();
                    //}
                }
                catch (Exception)
                {
                    transaction.Rollback();
                }
            }
        });
 }

What am I doing wrong? Perhaps there's another way to prevent the user from deleting himself?

Edit : I forgot to add that the method inst on a controller, but a class I created called lusuarios. Seems like all tutorials I checked online all do it on the controller.

Answer 1

On top of what I did I added IHttpContextAccessor httpContextAccessor to the class like this :

public Lusuario(
             UserManager<IdentityUser> userManager,
            SignInManager<IdentityUser> signInManager,
            RoleManager<IdentityRole> roleManager,
            ApplicationDbContext context,
            IWebHostEnvironment environment,
            IHttpContextAccessor httpContextAccessor)
        {
            _userManager = userManager;
            _roleManager = roleManager;
            _signInManager = signInManager;
            _context = context;
            _environment = environment;
            _userRole = new LUsuariosRoles();
            _uploadimage = new LUploadimage();
            _httpContextAccessor = httpContextAccessor;
        }

then I had to add it on: HomeController, PerfilController and on my class Details, like this on all of them

 public HomeController(
            UserManager<IdentityUser> userManager,
            SignInManager<IdentityUser> signInManager,
            RoleManager<IdentityRole> roleManager,
            ApplicationDbContext context,
            IServiceProvider serviceProvider,
            IHttpContextAccessor httpContextAccessor)
        {
            //_serviceProvider = serviceProvider;
            _signInManager = signInManager;
            _usuario = new Lusuario(userManager, signInManager, roleManager, context, null, httpContextAccessor);
        }

then var userId = _httpContextAccessor.HttpContext.User.FindFirst(ClaimTypes.NameIdentifier).Value; no longer returned null and I could compare the currently logged user ID with the one that was getting deleted.