如何在Flutter中通过键盘堆叠容器，类似于聊天中的WhatsApp "more“部分

import 'package:flutter/material.dart';

class ChatScreen extends StatefulWidget {
  @override
  _ChatScreenState createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Chat'),
      ),
      body: Stack(
        children: [
          // 聊天消息列表
          ListView(
            children: [
              // 聊天消息组件
              // ...
            ],
          ),
          // 更多选项部分
          Positioned(
            bottom: 0,
            left: 0,
            right: 0,
            child: Container(
              color: Colors.white,
              padding: EdgeInsets.all(16),
              child: Row(
                children: [
                  // 更多选项按钮
                  // ...
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}