public ActionResult Search(int?tinhThanhPhoId, int?quanHuyenId, int?loaiDuAnId, int?trangThai)
        {
            var viewModel = new QuanLyDuAnViewModel {
                LoaiDuAns     = _context.LoaiDuAns.ToList(),
                TinhThanhPhos = _context.TinhThanhPhos.ToList(),
                QuanHuyens    = _context.QuanHuyens.ToList(),
                DuAns         = _context.DuAns.Include(x => x.TinhThanhPho).Include(x => x.QuanHuyen).Include(y => y.LoaiDuAn).ToList(),
                TrangThaiDuAn = SelectOptions.getTrangThaiDuAn
            };

            if (tinhThanhPhoId.HasValue)
            {
                viewModel.TinhThanhPhoId = tinhThanhPhoId.Value;
                viewModel.DuAns          = viewModel.DuAns.Where(x => x.TinhThanhPho.Id == tinhThanhPhoId);
            }

            if (quanHuyenId.HasValue)
            {
                viewModel.QuanHuyenId = quanHuyenId.Value;
                viewModel.DuAns       = viewModel.DuAns.Where(x => x.QuanHuyen.Id == quanHuyenId);
            }

            if (loaiDuAnId.HasValue)
            {
                viewModel.LoaiDuAnId = loaiDuAnId.Value;
                viewModel.DuAns      = viewModel.DuAns.Where(x => x.LoaiDuAn.Id == loaiDuAnId);
            }

            if (trangThai.HasValue)
            {
                viewModel.TrangThai = trangThai.Value;
                viewModel.DuAns     = viewModel.DuAns.Where(x => x.TrangThai == trangThai);
            }

            return(View("Index", viewModel));
        }
        // GET: Admin/QuanLyDuAn
        public ActionResult Index()
        {
            if (TempData["success"] != null)
            {
                ViewBag.Success = TempData["success"].ToString();
                TempData.Remove("success");
            }
            if (TempData["error"] != null)
            {
                ViewBag.Error = TempData["error"].ToString();
                TempData.Remove("error");
            }

            var viewModel = new QuanLyDuAnViewModel
            {
                LoaiDuAns     = _context.LoaiDuAns.ToList(),
                TinhThanhPhos = _context.TinhThanhPhos.ToList(),
                QuanHuyens    = _context.QuanHuyens.ToList(),
                DuAns         = _context.DuAns.Include(x => x.TinhThanhPho).Include(x => x.QuanHuyen).Include(y => y.LoaiDuAn).ToList(),
                TrangThaiDuAn = SelectOptions.getTrangThaiDuAn
            };

            return(View(viewModel));
        }