public void HienThiThongKe()
{
int i = 0;
List <ThongKe> tklist = tkbll.ThongKeDonDatHang();
dgvThongKeDonHang.Rows.Clear();
foreach (ThongKe tks in tklist)
{
DataGridViewRow row = new DataGridViewRow();
row.CreateCells(dgvThongKeDonHang);
row.Cells[0].Value = i + 1;
row.Cells[1].Value = tks.MaSp;
row.Cells[2].Value = tks.TenSp;
row.Cells[3].Value = tks.TenLoai;
row.Cells[4].Value = tks.TenSx;
row.Cells[5].Value = tks.Sld;
dgvThongKeDonHang.Rows.Add(row);
++i;
}
cboTongDondh.Text = i.ToString();
}