public async Task <IActionResult> EditRole(string id)
        {
            var role = await roleMenager.FindByIdAsync(id);

            var model = new EditRoleModelView
            {
                Id       = role.Id,
                RoleName = role.Name
            };

            foreach (var user in await userMenager.Users.ToListAsync())
            {
                if (await userMenager.IsInRoleAsync(user, role.Name))
                {
                    model.Users.Add(user.UserName);
                }
            }
            return(View(model));
        }
        public async Task <IActionResult> EditRole(EditRoleModelView model)
        {
            if (ModelState.IsValid)
            {
                var role = await roleMenager.FindByIdAsync(model.Id);

                role.Name = model.RoleName;
                var result = await roleMenager.UpdateAsync(role);

                if (result.Succeeded)
                {
                    return(RedirectToAction("ListRoles"));
                }
                foreach (var error in result.Errors)
                {
                    ModelState.AddModelError("", error.Description);
                }
            }
            return(View(model));
        }