gistfile1.cs

public class AdminController : Controller
    {
        private readonly IRepository<Category> repository;

        public AdminController(IRepository<Category> repository)
        {
            this.repository = repository;
        }

        public ViewResult Categories()
        {
            var categoriesListViewModel = new CategoriesListViewModel();

            repository.GetAll().ForEach(x => categoriesListViewModel.Categories.Add(x));

            return View("Categories", categoriesListViewModel);
        }

        [HttpGet]
        public ActionResult CategoriesAdd()
        {
            return View("CategoriesAdd");
        }

        [HttpPost]
        [ActionName("CategoriesAdd")]
        public ActionResult CategoriesAdd(CategoriesAddViewModel viewModel)
        {
            repository.Save(new Category
                                {
                                    Id = Guid.NewGuid().ToString(),
                                    Name = viewModel.CategoryName,
                                    Enabled = viewModel.Enabled
                                });

            return RedirectToAction("Categories", "Admin");
        }
    }