private void Form_HoaDon_Load(object sender, EventArgs e) { BUS_HoaDon hd = new BUS_HoaDon(); DataTable tbl = hd.DSMatHang(); dataGridView2.DataSource = tbl; for (int i = 0; i < dataGridView2.Rows.Count; i++) { cmbList.Items.Add(dataGridView2.Rows[i].Cells["tenmathang"].Value.ToString()); } CloseTextBox(); }