public IActionResult Index(string thongbao)
        {
            List <HangSanPham> hang = ctx.HangSanPham.ToList();

            ViewBag.Hang = hang;
            //Thông báo
            if (thongbao != null)
            {
                ViewBag.ThongBao = thongbao;
            }
            SanPhamBUS     sanphambus = new SanPhamBUS();
            List <SanPham> spnam      = sanphambus.GetSanPhams("PhanLoai", "Nam", pagenumber, pagesize);
            List <SanPham> spnu       = sanphambus.GetSanPhams("PhanLoai", "Nữ", pagenumber, pagesize);
            List <SanPham> spmoi      = sanphambus.GetSanPhams("", "", pagenumber, pagesize);
            List <SanPham> spbanchay  = sanphambus.GetBanChay();

            ViewBag.SanPhamNam     = spnam;
            ViewBag.SanPhamNu      = spnu;
            ViewBag.SanPhamMoi     = spmoi;
            ViewBag.SanPhamBanChay = spbanchay;
            return(View());
        }