如何从子无状态小部件设置有状态小部件的状态

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

class _ParentWidgetState extends State<ParentWidget> {
  String _text = 'Initial Text';

  void _updateText(String newText) {
    setState(() {
      _text = newText;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Parent Widget'),
      ),
      body: Column(
        children: [
          Text(_text),
          ChildWidget(updateText: _updateText), // Pass the callback function
        ],
      ),
    );
  }
}

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

  ChildWidget({required this.updateText});

  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: () {
        updateText('New Text from Child'); // Call the callback to update state
      },
      child: Text('Change Text'),
    );
  }
}