private void btn_printchar_Click(object sender, EventArgs e) { if (_currenthumanid != 0) { List <int> checkedtestids = new List <int>(); foreach (DataGridViewRow row in dg_testresults.Rows) { if ((bool)row.Cells[2].Value == true) { checkedtestids.Add(Convert.ToInt16(row.Cells[0].Value)); } } IReference reference = _referfactory.GetReference(checkedtestids, (EnumPReferences)_currentref); if (reference != null) { reference.Print(); } } }