public DashboardWindow()
        {
            InitializeComponent();
            Global.Books          = SachBUS.loadAll();
            Global.Categories     = TheLoaiBUS.loadAllAndConvertToFillCombobox();
            Global.BookCategories = TheLoaiBUS.loadAll();
            Global.Customers      = KhachHangBUS.loadAll();
            KiemTraQuyDinh kt = QuyDinhBUS.loadKiemTraQuyDinh();

            Global.ControlRules = kt;


            var rules = QuyDinhBUS.loadQuyDinh();

            Global.quyDinh         = rules;
            Global.BookBoughtBills = new List <ChiTietHoaDonBanSachDTO>();
        }