private void deleteButton_Click(object sender, RoutedEventArgs e) { if (supplierTabControl.IsSelected) { if (selectedSupplier != null) { foreach (ISupplier supplier in suppliersDataGrid.SelectedItems) { supplierController.DeleteSupplier(supplier); } suppliersDataGrid.SelectedItem = null; refreshDataGrid(); } } else if (paymentRuleTabControl.IsSelected) { if (selectedPaymentRule != null) { foreach (IPaymentRule paymentRule in paymentRuleDataGrid.SelectedItems) { supplierController.DeletePaymentRule(paymentRule); } paymentRuleDataGrid.SelectedItem = null; refreshPaymentRuleDataGrid(); } } }