[asp.net] How to get the current logged in user Id in ASP.NET Core

I've done this before with MVC5 using User.Identity.GetUserId() but that doesn't seem to work here. The User.Identity doesnt have the GetUserId() method

I am using Microsoft.AspNet.Identity

in the APiController

User.FindFirst(ClaimTypes.NameIdentifier).Value

Something like this you will get the claims

In .net core 3.1 (and other more recent versions), you can use:

private readonly UserManager<IdentityUser> _userManager;

public ExampleController(UserManager<IdentityUser> userManager)
{
    _userManager = userManager;
}

Then:

string userId = _userManager.GetUserId(User);

Or async:

var user = await _userManager.GetUserAsync(User);
var userId = user.Id;

At this point, I'm trying to figure out why you'd use one over the other. I know the general benefits of async, but see both of these used frequently. Please post some comments if anyone knows.

Update in ASP.NET Core Version >= 2.0

In the Controller:

public class YourControllerNameController : Controller
{
    private readonly UserManager<ApplicationUser> _userManager;
    
    public YourControllerNameController(UserManager<ApplicationUser> userManager)
    {
        _userManager = userManager;
    }

    public async Task<IActionResult> YourMethodName()
    {
        var userId =  User.FindFirstValue(ClaimTypes.NameIdentifier) // will give the user's userId
        var userName =  User.FindFirstValue(ClaimTypes.Name) // will give the user's userName
        
        // For ASP.NET Core <= 3.1
        ApplicationUser applicationUser = await _userManager.GetUserAsync(User);
        string userEmail = applicationUser?.Email; // will give the user's Email

       // For ASP.NET Core >= 5.0
       var userEmail =  User.FindFirstValue(ClaimTypes.Email) // will give the user's Email
    }
}

In some other class:

public class OtherClass
{
    private readonly IHttpContextAccessor _httpContextAccessor;
    public OtherClass(IHttpContextAccessor httpContextAccessor)
    {
       _httpContextAccessor = httpContextAccessor;
    }

   public void YourMethodName()
   {
      var userId = _httpContextAccessor.HttpContext.User.FindFirstValue(ClaimTypes.NameIdentifier);
   }
}

Then you should register IHttpContextAccessor in the Startup class as follows:

public void ConfigureServices(IServiceCollection services)
{
    services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();

    // Or you can also register as follows

    services.AddHttpContextAccessor();
}

For more readability write extension methods as follows:

public static class ClaimsPrincipalExtensions
{
    public static T GetLoggedInUserId<T>(this ClaimsPrincipal principal)
    {
        if (principal == null)
            throw new ArgumentNullException(nameof(principal));

        var loggedInUserId = principal.FindFirstValue(ClaimTypes.NameIdentifier);

        if (typeof(T) == typeof(string))
        {
            return (T)Convert.ChangeType(loggedInUserId, typeof(T));
        }
        else if (typeof(T) == typeof(int) || typeof(T) == typeof(long))
        {
            return loggedInUserId != null ? (T)Convert.ChangeType(loggedInUserId, typeof(T)) : (T)Convert.ChangeType(0, typeof(T));
        }
        else
        {
            throw new Exception("Invalid type provided");
        }
    }

    public static string GetLoggedInUserName(this ClaimsPrincipal principal)
    {
        if (principal == null)
            throw new ArgumentNullException(nameof(principal));

        return principal.FindFirstValue(ClaimTypes.Name);
    }

    public static string GetLoggedInUserEmail(this ClaimsPrincipal principal)
    {
        if (principal == null)
            throw new ArgumentNullException(nameof(principal));

        return principal.FindFirstValue(ClaimTypes.Email);
    }
}

Then use as follows:

public class YourControllerNameController : Controller
{
    public IActionResult YourMethodName()
    {
        var userId = User.GetLoggedInUserId<string>(); // Specify the type of your UserId;
        var userName = User.GetLoggedInUserName();
        var userEmail = User.GetLoggedInUserEmail();
    }
}

public class OtherClass
{
     private readonly IHttpContextAccessor _httpContextAccessor;
     public OtherClass(IHttpContextAccessor httpContextAccessor)
     {
         _httpContextAccessor = httpContextAccessor;
     }

     public void YourMethodName()
     {
         var userId = _httpContextAccessor.HttpContext.User.GetLoggedInUserId<string>(); // Specify the type of your UserId;
     }
}

For ASP.NET Core 2.0, Entity Framework Core 2.0, AspNetCore.Identity 2.0 api (https://github.com/kkagill/ContosoUniversity-Backend):

The Id was changed to User.Identity.Name

    [Authorize, HttpGet("Profile")]
    public async Task<IActionResult> GetProfile()
    {
        var user = await _userManager.FindByIdAsync(User.Identity.Name);

        return Json(new
        {
            IsAuthenticated = User.Identity.IsAuthenticated,
            Id = User.Identity.Name,
            Name = $"{user.FirstName} {user.LastName}",
            Type = User.Identity.AuthenticationType,
        });
    }

Response:

For .NET Core 2.0 Only The following is required to fetch the UserID of the logged-in User in a Controller class:

var userId = this.User.FindFirstValue(ClaimTypes.NameIdentifier);

or

var userId = HttpContext.User.FindFirstValue(ClaimTypes.NameIdentifier);

e.g.

contact.OwnerID = this.User.FindFirstValue(ClaimTypes.NameIdentifier);

you can get it in your controller:

using System.Security.Claims;
var userId = this.User.FindFirstValue(ClaimTypes.NameIdentifier);

or write an extension method like before .Core v1.0

using System;
using System.Security.Claims;

namespace Shared.Web.MvcExtensions
{
    public static class ClaimsPrincipalExtensions
    {
        public static string GetUserId(this ClaimsPrincipal principal)
        {
            if (principal == null)
                throw new ArgumentNullException(nameof(principal));

            return principal.FindFirst(ClaimTypes.NameIdentifier)?.Value;
        }
    }
}

and get wherever user ClaimsPrincipal is available :

using Microsoft.AspNetCore.Mvc;
using Shared.Web.MvcExtensions;

namespace Web.Site.Controllers
{
    public class HomeController : Controller
    {
        public IActionResult Index()
        {
            return Content(this.User.GetUserId());
        }
    }
}

you have to import Microsoft.AspNetCore.Identity & System.Security.Claims

// to get current user ID
var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);

// to get current user info
var user = await _userManager.FindByIdAsync(userId);

As stated somewhere in this post, the GetUserId() method has been moved to the UserManager.

private readonly UserManager<ApplicationUser> _userManager;

public YourController(UserManager<ApplicationUser> userManager)
{
    _userManager = userManager;
}

public IActionResult MyAction()
{
    var userId = _userManager.GetUserId(HttpContext.User);

    var model = GetSomeModelByUserId(userId);

    return View(model);
}

If you started an empty project you might need to add the UserManger to your services in startup.cs. Otherwise this should already be the case.

Make sure that you have enable windows authentication. If you have anonymous authentication enabled you may be getting a null string.

https://docs.microsoft.com/en-us/aspnet/core/security/authentication/windowsauth?view=aspnetcore-3.1&tabs=visual-studio

Until ASP.NET Core 1.0 RC1 :

It's User.GetUserId() from System.Security.Claims namespace.

Since ASP.NET Core 1.0 RC2 :

You now have to use UserManager. You can create a method to get the current user :

private Task<ApplicationUser> GetCurrentUserAsync() => _userManager.GetUserAsync(HttpContext.User);

And get user information with the object :

var user = await GetCurrentUserAsync();

var userId = user?.Id;
string mail = user?.Email;

Note : You can do it without using a method writing single lines like this string mail = (await _userManager.GetUserAsync(HttpContext.User))?.Email, but it doesn't respect the single responsibility principle. It's better to isolate the way you get the user because if someday you decide to change your user management system, like use another solution than Identity, it will get painful since you have to review your entire code.

Although Adrien's answer is correct, you can do this all in single line. No need for extra function or mess.

It works I checked it in ASP.NET Core 1.0

var user = await _userManager.GetUserAsync(HttpContext.User);

then you can get other properties of the variable like user.Email. I hope this helps someone.

use can use

string userid = User.FindFirst("id").Value;

for some reason NameIdentifier now retrieve the username (.net core 2.2)

As an administrator working on other people's profile and you need to get the Id of the profile you are working on, you can use a ViewBag to capture the Id e.g ViewBag.UserId = userId; while userId is the string Parameter of the method you are working on.

    [HttpGet]

    public async Task<IActionResult> ManageUserRoles(string userId)
    {

          ViewBag.UserId = userId;


        var user = await userManager.FindByIdAsync(userId);

        if (user == null)
        {
            ViewBag.ErrorMessage = $"User with Id = {userId} cannot be found";
            return View("NotFound");
        }

        var model = new List<UserRolesViewModel>();

        foreach (var role in roleManager.Roles)
        {
            var userRolesViewModel = new UserRolesViewModel
            {
                RoleId = role.Id,
                RoleName = role.Name
            };

            if (await userManager.IsInRoleAsync(user, role.Name))
            {
                userRolesViewModel.IsSelected = true;
            }
            else
            {
                userRolesViewModel.IsSelected = false;
            }

            model.Add(userRolesViewModel);
        }
        return View(model);
    }

For getting current user id in razor views, we can inject UserManager in the view like this:

@inject Microsoft.AspNetCore.Identity.UserManager<ApplicationUser> _userManager
@{ string userId = _userManager.GetUserId(User); }

I hope you find it useful.

If you want this in ASP.NET MVC Controller, use

using Microsoft.AspNet.Identity;

User.Identity.GetUserId();

You need to add using statement because GetUserId() won't be there without it.

For ASP.NET 5.0, I have an extension method as follow:

using System;
using System.ComponentModel;
using System.Security.Claims;

namespace YOUR_PROJECT.Presentation.WebUI.Extensions
{
    public static class ClaimsPrincipalExtensions
    {
        public static TId GetId<TId>(this ClaimsPrincipal principal)
        {
            if (principal == null || principal.Identity == null || 
                !principal.Identity.IsAuthenticated)
            {
                throw new ArgumentNullException(nameof(principal));
            }

            var loggedInUserId = principal.FindFirstValue(ClaimTypes.NameIdentifier);

            if (typeof(TId) == typeof(string) || 
                typeof(TId) == typeof(int) || 
                typeof(TId) == typeof(long) || 
                typeof(TId) == typeof(Guid))
            {
                var converter = TypeDescriptor.GetConverter(typeof(TId));

                return (TId)converter.ConvertFromInvariantString(loggedInUserId);
            }

            throw new InvalidOperationException("The user id type is invalid.");
        }

        public static Guid GetId(this ClaimsPrincipal principal)
        {
            return principal.GetId<Guid>();
        }
    }
}

So you can use it like:

using Microsoft.AspNetCore.Mvc;
using YOUR_PROJECT.Presentation.WebUI.Extensions;

namespace YOUR_PROJECT.Presentation.WebUI.Controllers
{
    public class YourController :Controller
    {
        public IActionResult YourMethod()
        {
            // If it's Guid
            var userId = User.GetId();

            // Or
            // var userId = User.GetId<int>();

            return View();
        }
    }
}

User.Identity.GetUserId();

does not exist in asp.net identity core 2.0. in this regard, i have managed in different way. i have created a common class for use whole application, because of getting user information.

create a common class PCommon & interface IPCommon adding reference using System.Security.Claims

using Microsoft.AspNetCore.Http;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;

namespace Common.Web.Helper
{
    public class PCommon: IPCommon
    {
        private readonly IHttpContextAccessor _context;
        public PayraCommon(IHttpContextAccessor context)
        {
            _context = context;
        }
        public int GetUserId()
        {
            return Convert.ToInt16(_context.HttpContext.User.FindFirstValue(ClaimTypes.NameIdentifier));
        }
        public string GetUserName()
        {
            return _context.HttpContext.User.Identity.Name;
        }

    }
    public interface IPCommon
    {
        int GetUserId();
        string GetUserName();        
    }    
}

Here the implementation of common class

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.Extensions.Logging;
using Pay.DataManager.Concreate;
using Pay.DataManager.Helper;
using Pay.DataManager.Models;
using Pay.Web.Helper;
using Pay.Web.Models.GeneralViewModels;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Pay.Controllers
{

    [Authorize]
    public class BankController : Controller
    {

        private readonly IUnitOfWork _unitOfWork;
        private readonly ILogger _logger;
        private readonly IPCommon _iPCommon;


        public BankController(IUnitOfWork unitOfWork, IPCommon IPCommon, ILogger logger = null)
        {
            _unitOfWork = unitOfWork;
            _iPCommon = IPCommon;
            if (logger != null) { _logger = logger; }
        }


        public ActionResult Create()
        {
            BankViewModel _bank = new BankViewModel();
            CountryLoad(_bank);
            return View();
        }

        [HttpPost, ActionName("Create")]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Insert(BankViewModel bankVM)
        {

            if (!ModelState.IsValid)
            {
                CountryLoad(bankVM);
                //TempData["show-message"] = Notification.Show(CommonMessage.RequiredFieldError("bank"), "Warning", type: ToastType.Warning);
                return View(bankVM);
            }


            try
            {
                bankVM.EntryBy = _iPCommon.GetUserId();
                var userName = _iPCommon.GetUserName()();
                //_unitOfWork.BankRepo.Add(ModelAdapter.ModelMap(new Bank(), bankVM));
                //_unitOfWork.Save();
               // TempData["show-message"] = Notification.Show(CommonMessage.SaveMessage(), "Success", type: ToastType.Success);
            }
            catch (Exception ex)
            {
               // TempData["show-message"] = Notification.Show(CommonMessage.SaveErrorMessage("bank"), "Error", type: ToastType.Error);
            }
            return RedirectToAction(nameof(Index));
        }



    }
}

get userId and name in insert action

_iPCommon.GetUserId();

Thanks, Maksud