public ActionResult EditTrainer(TrainerViewModelInStaff model)
        {
            var findTrainer = _context.Users.OfType <Trainer>().SingleOrDefault(t => t.Id == model.Id);

            findTrainer.TrainerName  = model.TrainerName;
            findTrainer.TypeId       = model.TypeId;
            findTrainer.WorkingPlace = model.WorkingPlace;
            _context.SaveChanges();
            return(RedirectToAction("AllTrainer"));
        }
        public ActionResult EditTrainer(string Id)
        {
            var findTrainer = _context.Users.OfType <Trainer>().Include(t => t.Type).SingleOrDefault(t => t.Id == Id);

            if (findTrainer == null)
            {
                return(HttpNotFound());
            }
            TrainerViewModelInStaff model = new TrainerViewModelInStaff()
            {
                Id           = findTrainer.Id,
                TrainerName  = findTrainer.TrainerName,
                Email        = findTrainer.Email,
                WorkingPlace = findTrainer.WorkingPlace,
                Type         = findTrainer.Type,
                Types        = _context.Types.ToList()
            };

            return(View(model));
        }