如何从其他StatefulWidget更新StatefulWidget？

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

class _ParentWidgetState extends State<ParentWidget> {
  void _updateChildState() {
    setState(() {
      // 触发重建，调用_childWidgetKey.currentState.updateState()
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Parent Widget'),
      ),
      body: Center(
        child: ChildWidget(key: ValueKey('childWidget'), updateState: _updateChildState),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _updateChildState,
        child: Icon(Icons.refresh),
      ),
    );
  }
}

class ChildWidget extends StatefulWidget {
  final Function updateState;
  ChildWidget({Key? key, required this.updateState}) : super(key: key);

  @override
  _ChildWidgetState createState() => _ChildWidgetState();
}

class _ChildWidgetState extends State<ChildWidget> {
  String _text = 'Initial Text';

  void updateState() {
    setState(() {
      _text = 'Updated Text';
    });
  }

  @override
  Widget build(BuildContext context) {
    return Text(_text);
  }
}

dependencies:
  flutter:
    sdk: flutter
  provider: ^6.0.1

import 'package:flutter/material.dart';

class Counter with ChangeNotifier {
  int _count = 0;

  int get count => _count;

  void increment() {
    _count++;
    notifyListeners();
  }
}

class ParentWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      create: (context) => Counter(),
      child: Scaffold(
        appBar: AppBar(
          title: Text('Parent Widget'),
        ),
        body: Center(
          child: ChildWidget(),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            Provider.of<Counter>(context, listen: false).increment();
          },
          child: Icon(Icons.add),
        ),
      ),
    );
  }
}

class ChildWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final counter = Provider.of<Counter>(context);
    return Text('Count: ${counter.count}');
  }
}