HttpContext.GetOwinContext().GetUserManager() return null

Question

I\'ve used ASP.NET Identity 2 for creating role but the result of HttpContext.GetOwinContext().GetUserManager() was null.

Then I could

Answer 1

Most likely you have missed giving OwinContext the way to create ApplicationUserManager.
For that you'll need to have these in your public void Configuration(IAppBuilder app)

app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
app.CreatePerOwinContext<AppRoleManager>(AppRoleManager.Create);

This will register delegates that create UserManager and RoleManager with OwinContext and only after that you can call these back in your controllers.

Answer 2

I know it's old post , but I want to share my researches with others, for this issue I created partial class and add all my owin references there:

public partial class Startup
    {
        public void ConfigureAuth(IAppBuilder app)
        {
            // Configure the db context, user manager and signin manager to use a single instance per request
            app.CreatePerOwinContext(IdentityModels.Create);
            app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
            app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);
app.CreatePerOwinContext<AppRoleManager>(AppRoleManager.Create);

            app.UseCookieAuthentication(new CookieAuthenticationOptions
            {
                AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
                LoginPath = new PathString("/Account/Login"),
                Provider = new CookieAuthenticationProvider
                {
                    // Enables the application to validate the security stamp when the user logs in.
                    // This is a security feature which is used when you change a password or add an external login to your account.  
                    OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
                validateInterval: TimeSpan.FromMinutes(30),
                regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
                }
            });


        }
    }

then I utilize this method in other partial startup :

  public partial class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            ConfigureAuth(app);
        }
    }