Flutter:我怎么才能让抽屉在一开始就打开呢？

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter 抽屉示例'),
      ),
      drawer: Drawer(
        elevation: 16, // 设置抽屉的阴影高度
        child: Column(
          children: [
            UserAccountsDrawerHeader(
              accountName: Text('用户名'),
              accountEmail: Text('用户邮箱'),
              currentAccountPicture: CircleAvatar(
                child: Icon(Icons.person),
              ),
            ),
            ListTile(
              leading: Icon(Icons.home),
              title: Text('首页'),
              onTap: () {
                // 处理菜单项点击事件
              },
            ),
            ListTile(
              leading: Icon(Icons.settings),
              title: Text('设置'),
              onTap: () {
                // 处理菜单项点击事件
              },
            ),
          ],
        ),
      ),
      body: Center(
        child: Text('主要内容'),
      ),
    );
  }
}