private void RefreshDTGV() { dtgvThongKe.Rows.Clear(); int ID = dtgvThongKe.Rows.Count + 1; ThongKe NV = new ThongKe(); foreach (THONGKEDONHANGDABAN item in NV.ThongKeSanPham()) { dtgvThongKe.Rows.Add(ID, item.MADH, item.TENKH, item.TENNV, item.TIMEXUAT, item.THANHTIEN); ID++; } lbTongTien.Text = String.Format("{0:n0} VNĐ", NV.TongThanhTien()); }