public void Luu_PhieuBanHang(TextBox MaPBH, ComboBox MaKH, ComboBox MaNV, DateTimePicker NgayLap, TextBox TT)
        {
            PhieuBanHangData pbhdata = new PhieuBanHangData();
            DataTable        dt      = pbhdata.LayDSPBH();

            DataRow row = dt.NewRow();

            row[0] = MaPBH.Text;
            row[1] = MaKH.SelectedValue;
            row[2] = MaNV.SelectedValue;
            row[3] = NgayLap.Value.Date;
            row[4] = TT.Text;

            dt.Rows.Add(row);
            pbhdata.Update();
        }
        public void HienThiListView(ListView listview)
        {
            listview.Items.Clear();
            DataTable dtb = data.LayDSPBH();
            int       n   = 0;

            foreach (DataRow row in dtb.Rows)
            {
                ListViewItem item = new ListViewItem();
                n++;
                item.Text = n.ToString();
                item.SubItems.Add(row["MAPHIEU"].ToString());
                item.SubItems.Add(row["MAKH"].ToString());
                item.SubItems.Add(row["MANV"].ToString());
                item.SubItems.Add(row["NGAYLAP"].ToString());
                item.SubItems.Add(row["TONGTIEN"].ToString());

                listview.Items.Add(item);
            }
        }