public async Task <IActionResult> Create(LessonDto lessonDto)
{
if (await _lessonService.AreThereLesson(lessonDto.LessonName.ToLower(), lessonDto.FkGradeId) == false)
{
await _lessonService.AddAsync(_mapper.Map <Lesson>(lessonDto));
ViewBag.ErrorMessage = "";
return(RedirectToAction("GetAll", "Lesson"));
}
ViewBag.ErrorMessage = "Sistemde aynı isme ait ders bulunmaktadır...!";
return(View(lessonDto));
}