如何在Flutter中创建TextField框中的标题？

TextField(
  decoration: InputDecoration(
    labelText: '标题',
  ),
)

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'TextField示例',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('TextField示例'),
      ),
      body: Center(
        child: TextField(
          decoration: InputDecoration(
            labelText: '标题',
          ),
        ),
      ),
    );
  }
}