Web上底部表单（BottomSheet）中的自动聚焦文本框（TextField）没有跟随键盘。

这个问题可以通过在Scaffold的resizeToAvoidBottomInset属性中设置false来解决。当resizeToAvoidBottomInset属性为true时，Scaffold会调整其大小以避免底部缩进，但也会导致底部表单无法跟随键盘，从而出现该问题。设置为false后，Scaffold将不会自动调整大小，但是表单将会跟随键盘。下面是一个实现示例：

import 'package:flutter/material.dart';

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

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

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final _formKey = GlobalKey<FormState>();
  final _textController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('BottomSheet Autofocus'),
      ),
      resizeToAvoidBottomInset: false,
      body: Center(
        child: ElevatedButton(
          child: Text('Open BottomSheet'),
          onPressed: () {
            showModalBottomSheet(context: context, builder: (context) {
              return Container(
                padding: EdgeInsets.all(16.0),
                child: Form(
                  key: _formKey,
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Text('Enter your name:'),
                      TextFormField(
                        autofocus: true,
                        controller: _textController,
                        validator: (value) {
                          if (value == null || value.isEmpty) {
                            return 'Please enter your name';
                          }
                          return null;
                        },
                      ),
                      SizedBox(height: 8.0),
                      ElevatedButton(
                        child: Text('Save'),
                        onPressed: () {
                          if (_formKey.currentState.validate()) {
                            Navigator.of(context).pop();