public ActionResult ChangeAttach(ChangeAttachPageViewModel model)
        {
            var pageRepository = new PagesRepository();
            var regionRepository = new RegionsRepository();

            var region = regionRepository.GetById(model.Id);

            if (model.PageId.HasValue && model.PageId != region.PageId)
            {
                var page = pageRepository.GetById(model.PageId.Value);

                region.PageId = page.Id;
                region.Page = page;

                regionRepository.Update(region);
            }
            else
            {
                if (model.OldPageId.HasValue)
                {
                    region.PageId = null;
                    region.Page = null;

                    regionRepository.Update(region);
                }
            }

            return RedirectToAction("Details", new { id = model.Id });
        }
        // GET: BaseLayers/Create
        public ActionResult ChangeAttach(long id)
        {
            var regionsRepository = new RegionsRepository();
            var pagesRepository = new PagesRepository();

            var region = regionsRepository.GetById(id);

            IDisposable context = null;

            ViewBag.ListOfPages = pagesRepository.GetAll(out context).ToList().Select(x => new SelectListItem()
            {
                Value = x.Id.ToString(),
                Text = x.Name,
                Selected = region != null && region.PageId == x.Id
            });

            context?.Dispose();

            var model = new ChangeAttachPageViewModel()
            {
                Id = id,
                OldPageId = region?.PageId
            };

            return PartialView(model);
        }
        public ActionResult ChangeAttach(ChangeAttachPageViewModel model)
        {
            var pageRepository = new PagesRepository();
            var pointRepository = new PointsRepository();

            var point = pointRepository.GetById(model.Id);

            if (model.PageId.HasValue && model.PageId != point.PageId)
            {
                var page = pageRepository.GetById(model.PageId.Value);

                point.PageId = page.Id;
                point.Page = page;

                pointRepository.Update(point);
            }
            else
            {
                if (model.OldPageId.HasValue)
                {
                    point.PageId = null;
                    point.Page = null;

                    pointRepository.Update(point);
                }
            }

            return RedirectToAction("Details", new { id = model.Id });
        }