No service for type 'Microsoft.AspNetCore.Identity.RoleManager error

Question

I'm setting up user roles on a ASP.NET CORE 2.1 application. But when I try to use the RoleManager it shoots into error. The error I get is:

No service for type 'Microsoft.AspNetCore.Identity.RoleManager`1[Microsoft.AspNetCore.Identity.IdentityRole]' has been registered.)'

I've looked through the whole application to see if IdentityUser is still anywhere, since I've created a class that inherits from it ( ApplicationUser ), but everything else seems correct. Adding services.AddIdentity<ApplicationUser, IdentityRole>() .AddEntityFrameworkStores<ApplicationDbContext>() .AddDefaultTokenProviders(); gives a runtime error stating: NotSupportedException: Store does not implement IUserRoleStore<TUser>. Adding Service.AddDefaultIdentity()instead of AddIdentity()doesn't work either.

public class Startup
{

    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.Configure<CookiePolicyOptions>(options =>
        {
            // This lambda determines whether user consent for non-essential cookies is needed for a given request.
            options.CheckConsentNeeded = context => true;
            options.MinimumSameSitePolicy = SameSiteMode.None;
        });

        //services.AddDbContext<ApplicationDBContext>(options => options.UseSqlServer(Configuration.GetConnectionString("ApplicationDBContextConnection")));


        //services.AddDefaultIdentity<ApplicationUser>().AddRoles<IdentityRole>().AddEntityFrameworkStores<ApplicationDBContext>();

        services.Configure<IdentityOptions>(options =>
        {
            // Password settings
            options.Password.RequireDigit = true;
            options.Password.RequiredLength = 8;
            options.Password.RequireNonAlphanumeric = false;
            options.Password.RequireUppercase = true;
            options.Password.RequireLowercase = false;
            options.Password.RequiredUniqueChars = 6;

            // Lockout settings
            options.Lockout.DefaultLockoutTimeSpan = TimeSpan.FromMinutes(30);
            options.Lockout.MaxFailedAccessAttempts = 10;
            options.Lockout.AllowedForNewUsers = true;

            // User settings
            options.User.RequireUniqueEmail = true;
        });

        services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env, UserManager<ApplicationUser> userManager)
    {


        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy();
        app.UseAuthentication();


        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });

        CreateUserRoles(userManager).GetAwaiter().GetResult();
    }
    private async Task CreateUserRoles( UserManager<ApplicationUser> userManager)
    {

        var UserManager = userManager;

        //Assign Admin role to the main User here we have given our newly registered 
        //login id for Admin management
        ApplicationUser user = await UserManager.FindByEmailAsync("[email protected]");
        UserManager.AddToRoleAsync(user, "Admin").GetAwaiter().GetResult();
    }
}

Answer 1

I have figured it out.

I created a new ApplicationUser class, which inherited from it IdentityUser. Afterwards I ran the Identity scaffolder, stating to use my ApplicationUser as the new class.

While doing that .NET CORE created an additional class:

    public class IdentityHostingStartup : IHostingStartup
{
    public void Configure(IWebHostBuilder builder)
    {
        builder.ConfigureServices((context, services) => {
            services.AddDbContext<ApplicationDBContext>(options =>
                options.UseSqlServer(
                    context.Configuration.GetConnectionString("ApplicationDBContextConnection")));

            services.AddDefaultIdentity<ApplicationUser>()
                .AddEntityFrameworkStores<ApplicationDBContext>();
        });
    }
}

The configuration in this class overrides every option and service ( that has been declared ) in the startup class. And it will crash if you have identical options/services declared in both classes.. That's why It wasn't working. After adding .AddRoles<IdentityRole>() to the IdentityHostingStartUp everything is working!

I'm still looking for a way to rip out the IdentityHostingStartUp, just ripping out those declared there will let the application crash.

Answer 2

You can inject any registered service explicitly into the Configure() method.

public void Configure(RoleManager<IdentityRole> roleManager)

I'm not sure what is happening when you try to inject IServiceProvider, but it doesn't look correct.

Also, never use .Wait(), use .GetAwaiter().GetResult() instead.