/// <summary>
        /// Привязка аккаунта студента
        /// </summary>
        /// <param name="elGradebookGroupStudentId"></param>
        /// <returns></returns>
        public async Task <IActionResult> ElGradebookGroupStudentsBindAccount(int elGradebookGroupStudentId, string appUserLastNameFragment)
        {
            var entry = await _elGradebookRepository.GetElGradebookGroupStudentAsync(elGradebookGroupStudentId);

            if (entry == null)
            {
                return(NotFound());
            }


            if (!string.IsNullOrWhiteSpace(appUserLastNameFragment))
            {
                ViewBag.FindedAppUsers = _selectListRepository.GetSelectListAppUsersByFirstName(appUserLastNameFragment);
            }
            else
            {
                appUserLastNameFragment = entry.ElGradebookGroupStudentFio;
                ViewBag.FindedAppUsers  = _selectListRepository.GetSelectListAppUsersByFirstName(entry.ElGradebookGroupStudentFio);
            }

            ViewBag.AppUserLastNameFragment = appUserLastNameFragment;

            return(View(entry));
        }
        /// <summary>
        /// Добавление автора в справочник
        /// </summary>
        /// <returns></returns>
        public async Task <IActionResult> AddAuthor(UchPosobieAuthor uchPosobieAuthor, string fio, string selectedAppUserId)
        {
            if (!string.IsNullOrWhiteSpace(selectedAppUserId))
            {
                Author author = await _uchPosobiyaRepository.CreateAuthorByAppUserIdAsync(selectedAppUserId);

                uchPosobieAuthor.AuthorId = author.AuthorId;
                await _uchPosobiyaRepository.UpdateUchPosobieAuthorAsync(uchPosobieAuthor);

                return(RedirectToAction(nameof(Index)));
            }

            if (!string.IsNullOrWhiteSpace(fio))
            {
                ViewBag.FindedUsers = _selectListRepository.GetSelectListAppUsersByFirstName(fio);
            }
            ViewBag.fio = fio;
            return(View(uchPosobieAuthor));
        }