如何在Flutter中显示随机字符串

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

class RandomStringWidget extends StatefulWidget {
  @override
  _RandomStringWidgetState createState() => _RandomStringWidgetState();
}

class _RandomStringWidgetState extends State<RandomStringWidget> {
  String randomString = '';

  void generateRandomString() {
    setState(() {
      // 生成随机字符串
      final random = Random();
      const chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
      randomString = String.fromCharCodes(Iterable.generate(
          10, (_) => chars.codeUnitAt(random.nextInt(chars.length))));
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text(
          '随机字符串:',
          style: TextStyle(fontSize: 16),
        ),
        Text(
          randomString,
          style: TextStyle(fontSize: 24, fontWeight: FontWeight.bold),
        ),
        RaisedButton(
          onPressed: generateRandomString,
          child: Text('生成随机字符串'),
        ),
      ],
    );
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Random String Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('Random String Demo'),
        ),
        body: Center(
          child: RandomStringWidget(),
        ),
      ),
    );
  }
}