flutter搜索框修改hint

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

void main(List<String> args) => runApp(App());

class App extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return AppState();
  }

class AppState extends State<App> {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      localizationsDelegates: [
        CustomLocalizationDelegate(),
      ],
      home: Scaffold(
        body: 省略,
      ),
    );
  }
}

class CustomLocalizationDelegate extends LocalizationsDelegate<MaterialLocalizations> {
  const CustomLocalizationDelegate();
  
  @override
  bool isSupported(Locale locale) => locale.languageCode == 'zh-cn';
  
  @override
  Future<MaterialLocalizations> load(Locale locale) => SynchronousFuture<MaterialLocalizations>(const CustomLocalization());
  
  @override
  bool shouldReload(CustomLocalizationDelegate old) => false;
  
  @override
  String toString() => 'CustomLocalization.delegate(zh-cn)';
}


class CustomLocalization extends DefaultMaterialLocalizations {
  const CustomLocalization();
  
  //在这里设置搜索框的hint
  @override
  String get searchFieldLabel => "搜索";
}