如何从另一个StatefulWidget更新StatefulWidget页面？

import 'package:flutter/material.dart';

class ParentWidget extends StatefulWidget {
  @override
  _ParentWidgetState createState() => _ParentWidgetState();
}

class _ParentWidgetState extends State<ParentWidget> {
  String _data = '';

  void _updateData(String newData) {
    setState(() {
      _data = newData;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        ChildWidget(callback: _updateData),
        Text(_data),
      ],
    );
  }
}

class ChildWidget extends StatelessWidget {
  final Function(String) callback;

  ChildWidget({required this.callback});

  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: () {
        // 调用回调函数并传递需要更新的数据
        callback('New Data');
      },
      child: Text('Update Data'),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      body: ParentWidget(),
    ),
  ));
}