private void frmThemHoaDon_Load(object sender, EventArgs e) { //NguoiDungBUS nguoiDung = new NguoiDungBUS(); cbNhanVien.DataSource = ndBus.GetDataID_Ten(); cbNhanVien.DisplayMember = "tenND"; cbNhanVien.ValueMember = "maND"; cbMaMatHang.DataSource = kBus.GetDataID_TenSP(); cbMaMatHang.DisplayMember = "maMH"; cbMaMatHang.ValueMember = "maMH"; // dataThemMH.DataSource = kBus.GetDataThemMH(cbMaMatHang.SelectedValue.ToString()); }