How to inject RoleManager - asp.net

Question

I need to inject RoleManager into Controller using Ninject in ASP.NET MVC 5 application. I am totally new in DI and Ninject, so I am not fully understand what Ninject do. I use Ninject 3.3.4, standard RoleManager from Identity 2.0 and EF6.2. My bindings are below:
public class NinjectRegistrations : NinjectModule
{
public override void Load()
{
Bind<HeroesContext>().ToSelf();
Bind<IRepository<Hero>>().To<HeroRepository>();
Bind<IRepository<Ability>>().To<AbilityRepository>();
Bind<IUserStore<ApplicationUser>>().To<UserStore<ApplicationUser>>().WithConstructorArgument("context", new HeroesContext());
Bind<UserManager<ApplicationUser>>().ToSelf();
Bind<HttpContextBase>().ToMethod(ctx => new HttpContextWrapper(HttpContext.Current)).InTransientScope();
Bind<ApplicationSignInManager>().ToMethod(context =>
{
var cbase = new HttpContextWrapper(HttpContext.Current);
return cbase.GetOwinContext().Get<ApplicationSignInManager>();
});
Bind<ApplicationUserManager>().ToSelf();
Bind<IRoleStore<IdentityRole, string>>().To<RoleStore<IdentityRole, string, IdentityUserRole>>();
Bind<RoleManager<IdentityRole, string>>().ToSelf();
}
}
Before RoleManager I have successfully inject two repositories in HomeController, their work fine. Also I injected ApplicationUserManager in AdminController and AccountController and ApplicationSignInManager in AccountController, it seems their work fine too because I can log in. Current problem is connected with RoleManager, at first nothing worked at all. After some googling I found this question, it helped partly. Now when I try do get list of users using AdminController I get this and basic recommendations:
Ninject.ActivationException: Error activating DbConnection
No matching bindings are available, and the type is not self-bindable.
Activation path:
5) Injection of dependency DbConnection into parameter existingConnection of constructor of type DbContext
4) Injection of dependency DbContext into parameter context of constructor of type RoleStore{IdentityRole, string, IdentityUserRole}
3) Injection of dependency IRoleStore{IdentityRole, string} into parameter store of constructor of type RoleManager{IdentityRole, string}
2) Injection of dependency RoleManager{IdentityRole, string} into parameter roleManager of constructor of type AdminController
1) Request for AdminController
I tried to find solution, but found nothing useful. Below you can find code of AdminController's constructor, Application_Start() and context (I'm not sure it is needed). Please help, my hiring depends on this.
public class AdminController : Controller
{
private readonly ApplicationUserManager _userManager;
private readonly RoleManager<IdentityRole> _roleManager;
public AdminController(ApplicationUserManager userManager, RoleManager<IdentityRole> roleManager)
{
_userManager = userManager;
_roleManager = roleManager;
}
}
protected void Application_Start()
{
Database.SetInitializer<HeroesContext>(new DbInitializer());
AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
var registrations = new NinjectRegistrations();
var kernel = new StandardKernel(registrations);
kernel.Unbind<ModelValidatorProvider>();
DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
}
public class HeroesContext : IdentityDbContext<ApplicationUser>
{
public DbSet<Hero> Heroes { get; set; }
public DbSet<Ability> Abilities { get; set; }
public HeroesContext() : base("DefaultConnection", throwIfV1Schema: false)
{
}
public static HeroesContext Create()
{
return new HeroesContext();
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Hero>().HasMany(n => n.Abilities)
.WithRequired(n => n.Hero)
.HasForeignKey(n => n.HeroId);
}
}

Answer 1

I guess that your RoleStore class is expecting dependency of type DbContext. And since you don't have any binding to DbContext, Ninject falls back to implicit self-binding. That means it tries to create DbContext trough the constructor:
public DbContext(DbConnection existingConnection, bool contextOwnsConnection)
but before that it can't create DbConnection as explained in the message.
Solution is:
change your binding: Bind<DbContext>().To<HeroesContext>();
or change type of the dependency in RoleStore toHeroesContext