Flutter -如何在搜索时将搜索文本从一个小部件传递到它的另一个类小部件？

class SearchWidget extends StatefulWidget {
  @override
  _SearchWidgetState createState() => _SearchWidgetState();
}

class _SearchWidgetState extends State<SearchWidget> {
  String searchText = '';

  @override
  Widget build(BuildContext context) {
    return TextField(
      onChanged: (value) {
        setState(() {
          searchText = value;
        });
      },
    );
  }
}

class ResultWidget extends StatelessWidget {
  final String searchText;

  ResultWidget(this.searchText);

  @override
  Widget build(BuildContext context) {
    return Text('Search Text: $searchText');
  }
}

class ParentWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        SearchWidget(),
        ResultWidget(),
      ],
    );
  }
}