how sloved this problem SelectListItem

 public ActionResult AddUser()
        {
            if (ModelState.IsValid)
            {
                
                if (ViewData["Fill_Name_post"] == null && ViewData["Fill_Name_baker"] ==null)
                {
                ViewData["Fill_Name_post"] = ClassPost.GenerateNumbers();
                 ViewData["Fill_Name_baker"] = Classtypebaker.GenerateNumbers();
               }
                return View();
            }
            return View();
        }


[HttpPost]
       
        public ActionResult AddUser([Bind(Include = "FName, FFamily, FFamily,Fsenfi,Fholidays")]  User postData)
        {
            if (ModelState.IsValid)
            {
                 string status = "";
                User _User = new User();

                if (string.IsNullOrEmpty(postData.FName) || string.IsNullOrEmpty(postData.Fsenfi.ToString()) || string.IsNullOrEmpty(postData.FFamily) || string.IsNullOrEmpty(postData.Fholidays) || postData.FTypeBaker == 0 || postData.ID_post == 0)
                {
                    ViewBag.name = "test";
                      status = "0";
                }
                //todo: Add temp to repository
                if (postData == null)
                    return Json(false);
                //  int baker = _ClassPost.checkbaker(postData.);
                if (status == "1")
                {

                    db.Users.Add(postData);
                    db.SaveChanges();

                    
                }
                return View();
                //  else
                {

                  
                    // return Json(new { status }, JsonRequestBehavior.AllowGet);

                }
            }
            else
                return View();
        }

  public static List<SelectListItem> GenerateNumbers()
        {Context context = new Context();
            
            var numbers = (from p in context.Posts
                           select new SelectListItem
                           {
                               Text = p.FNamePost,
                               Value = p.ID_Post.ToString()
                           });
            return numbers.ToList();
        }