private void btThemHD_Click(object sender, EventArgs e) { if (txtThanhTien.Text == "0") { string mh, mk, mv; DateTime nx; int tt; mh = txtMaHD.Text.Trim(); mk = cbbMaKH.Text.Trim(); nx = Convert.ToDateTime(dtpNgayXuat.Text); tt = int.Parse(txtThanhTien.Text); mv = txtMaNV.Text.Trim(); DTOHoaDon hd = new DTOHoaDon(mh, mk, nx, tt, mv); try { int i = new BUSHoaDon().Add(hd); dgvHoaDon.DataSource = GetHD(); load(); xoatrangHD(); txtMaHD.Text = ""; } catch (SqlException ex) { MessageBox.Show(ex.Message); } } else { MessageBox.Show("Chưa Reset lại!"); } }