мой пример (текстовый контроллер)
class _CloneTextPageSnackbarState extends State<CloneTextPageSnackbar> {
bool _isLoading = false;
bool _isClickable = true;
bool _validateInput = true;
String _textField;
final _textController = TextEditingController();
List<String> _cloneTextList;
CloneFactory adsFactory;
CreateAdsList createAdsList;
@override void dispose() {
_textController.dispose();
super.dispose();
}