Possible dependency injection problem in asp.net core?

Question

I'm wrapping up on tutorial and cannot fix problem in my program. When I go to the my route I get internal server error like this :

An unhandled exception occurred while processing the request. InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.UserManager`1[AspNetCoreTodo.Models.ApplicationUser]' while attempting to activate 'AspNetCoreTodo.Controllers.TodoController'. Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, bool isDefaultParameterRequired)

InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.UserManager`1[AspNetCoreTodo.Models.ApplicationUser]' while attempting to activate 'AspNetCoreTodo.Controllers.TodoController'.

Judging by this I think the problem lies in my controller, to be specific in my index method. It has worked so far but I got this error when I was trying to find authorized user for todo list. Basically the code is here and I think the error may be in this line :

var items = await _todoItemService.GetIncompleteItemsAsync(currentUser);

Here is my code for controller :

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Threading.Tasks; 
using Microsoft.AspNetCore.Mvc;
using AspNetCoreTodo.Services;
using AspNetCoreTodo.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;

namespace AspNetCoreTodo.Controllers 
{
    [Authorize]
    public class TodoController : Controller
    {
    private readonly ITodoItemService _todoItemService;
    private readonly UserManager<ApplicationUser> _userManager;
    public TodoController(ITodoItemService todoItemService, UserManager<ApplicationUser> userManager)
    {
        _todoItemService = todoItemService;
        _userManager = userManager;
    }
    public async Task<IActionResult> Index()
    {
        var currentUser = await _userManager.GetUserAsync(User);
        //var   currentUser = await _userManagerFindByIdAsync
        if(currentUser == null)
        {
            return Challenge();
        }
        var items = await _todoItemService.GetIncompleteItemsAsync(currentUser);

        var model = new TodoViewModel()
        {
            Items = items
        };

        return View(model);

    }

Startup.cs //configuration

 public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlite(
                Configuration.GetConnectionString("DefaultConnection")));
        services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
            .AddEntityFrameworkStores<ApplicationDbContext>();
        services.AddControllersWithViews();
       services.AddRazorPages();
        services.AddMvc();
        services.AddAuthentication();
       services.AddScoped<ITodoItemService, TodoItemService>();
    }

I solved this but will leave this to anyone who may encounter a similar problem. What I had to do was replacing the IdentityUser with ApplicationUser in my startup.cs file and changing this 2 lines in _LoginPartial.cshtml :

@inject SignInManager IdentityUser SignInManager

@inject UserManager IdentityUser UserManager

with :

@inject SignInManager ApplicationUser SignInManager

@inject UserManager ApplicationUser UserManager

After that you should add type after IdentityDbContex so you would have something like this in your ApplicationDbContext.cs but only if you receive context error :

namespace AspNetCoreTodo.Data
{
    public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
    {
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
    }
    public DbSet<TodoItem> Items {get;  set;}
}

}

Answer 1

This line:

services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)

I believe should have ApplicationUser instead of IdentityUser as the generic parameter for AddDefaultIdentity.