public HoaDonVM GetHoaDonVM(string currentSort, int idBanAn, string trangThai, int pageIndex)
        {
            int count;
            IEnumerable <HoaDonMD> listHoaDonMD = _services.GetListHoaDonMD(idBanAn, trangThai, pageIndex, pageSize, out count);

            switch (currentSort)
            {
            case "BanAn_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.IdBanAn);
                break;

            case "BanAn_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.IdBanAn);
                break;

            case "ThoiGianLap_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.ThoiGianLap);
                break;

            case "ThoiGianLap_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.ThoiGianLap);
                break;

            case "ThoiGianThanhToan_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.ThoiGianThanhToan);
                break;

            case "ThoiGianThanhToan_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.ThoiGianThanhToan);
                break;

            case "TrangThai_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.TrangThai);
                break;

            case "TrangThai_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.TrangThai);
                break;

            case "TenNhanVien_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.TenNhanVien);
                break;

            case "TenNhanVien_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.TenNhanVien);
                break;

            case "ThanhTien_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.ThanhTien);
                break;

            case "ThanhTien_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.ThanhTien);
                break;

            case "IdHoaDon_ASC":
                listHoaDonMD = listHoaDonMD.OrderBy(s => s.Id);
                break;

            case "IdHoaDon_DESC":
                listHoaDonMD = listHoaDonMD.OrderByDescending(s => s.Id);
                break;
            }
            return(new HoaDonVM
            {
                ListHoaDonMD = new PaginatedList <HoaDonMD>(listHoaDonMD, pageIndex, pageSize, count)
            });
        }