private void btnConfirm_Click(object sender, EventArgs e) { if (IsBtnConfirmEnabled()) { try { List <TrainingGroup> selectedGroups = new List <TrainingGroup>(); foreach (object item in listBoxGroups.SelectedItems) { TrainingGroup group = (TrainingGroup)item.GetType() .GetProperty("Value") .GetValue(item, null); selectedGroups.Add(group); } object comboBoxItem = comboBoxFitnessLvl.SelectedItem; FitnessLevel fitnessLevel = (FitnessLevel)comboBoxItem .GetType().GetProperty("Value") .GetValue(comboBoxItem, null); mainController.AddClient( new Client(textBoxOib.Text, textBoxFirstName.Text, textBoxLastName.Text, dtpDateOfBirth.Value, textBoxPhoneNum.Text, dtpDateOfJoining.Value, fitnessLevel, textBoxNotes.Text, selectedGroups)); DialogResult = DialogResult.OK; } catch (IncompleteDataException) { MessageBox.Show("Nepotpuni ili neispravni podaci", "Greška!", MessageBoxButtons.OK, MessageBoxIcon.Error); } catch (OibAlreadyTakenException) { MessageBox.Show("Klijent s unesenim OIB-om već postoji", "Greška!", MessageBoxButtons.OK, MessageBoxIcon.Error); } } }