在Flutter中自定义创建的小部件中获取TextField的值

class MyCustomWidget extends StatelessWidget {
  final ValueChanged<String> onValueChanged;

  MyCustomWidget({required this.onValueChanged});

  @override
  Widget build(BuildContext context) {
    return TextField(
      onChanged: onValueChanged,
    );
  }
}

class MyApp extends StatelessWidget {
  String textFieldValue = '';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Column(
          children: [
            MyCustomWidget(
              onValueChanged: (value) {
                textFieldValue = value;
              },
            ),
            Text('TextField的值：$textFieldValue'),
          ],
        ),
      ),
    );
  }
}