private void btnDelete_Click(object sender, RoutedEventArgs e) { if (lstRole.SelectedIndex == -1) return; RoleHelper client = new RoleHelper(); try { client.DeleteRoleTemplate(user, ((RoleTemplate)lstRole.SelectedItem).RoleTemplateID); } catch (Exception ex) { MessageBox.Show(ex.Message); return; } finally { client.Close(); } MessageBox.Show("Operation succeded!"); loadRoles(); }