Flutter沉浸式透明状态栏-flutter自定义凸起BottomAppBar导航

import 'package:flutter/material.dart';
 
class CustomScaffold extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[
          // 背景图片或颜色
          Container(
            decoration: BoxDecoration(
              image: DecorationImage(
                image: AssetImage('assets/background.jpg'),
                fit: BoxFit.cover,
              ),
            ),
          ),
          // 内容
          SafeArea(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                // 标题和返回按钮
                Padding(
                  padding: const EdgeInsets.only(left: 16.0, top: 32.0),
                  child: Row(
                    children: <Widget>[
                      IconButton(
                        icon: Icon(Icons.arrow_back),
                        onPressed: () => Navigator.of(context).pop(),
                      ),
                      Spacer(),
                      Text(
                        '标题',
                        style: TextStyle(fontSize: 20.0, color: Colors.white),
                      ),
                    ],
                  ),
                ),
                // 主要内容
                Expanded(
                  child: Container(
                    color: Colors.transparent,
                    child: Center(
                      child: Text(
                        '这里是主要内容',
                        style: TextStyle(fontSize: 24.0, color: Colors.white),
                      ),
                    ),
                  ),
                ),
              ],
            ),
          ),
          // 凸起的BottomAppBar
          BottomAppBar(
            color: Colors.transparent,
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: <Widget>[
                IconButton(icon: Icon(Icons.home), onPressed: () {}),
                IconButton(icon: Icon(Icons.search), onPressed: () {}),
                IconButton(icon: Icon(Icons.add), onPressed: () {}),
              ],
            ),
          ),