如何在flutter中更改其他文本字段时自动更改标签值？

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String _textValue = '';

  void _updateLabel(String value) {
    setState(() {
      _textValue = value;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Flutter Auto Update Label'),
        ),
        body: Column(
          children: [
            TextField(
              onChanged: (value) {
                _updateLabel(value);
              },
            ),
            Text('Label: $_textValue'),
          ],
        ),
      ),
    );
  }
}