如何隐藏Appbar并在滚动画面中显示自定义容器小部件

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

class ScrollPage extends StatefulWidget {
  @override
  _ScrollPageState createState() => _ScrollPageState();
}

class _ScrollPageState extends State<ScrollPage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            // 设置为透明背景
            backgroundColor: Colors.transparent,
            // 隐藏标题
            title: null,
            // 隐藏阴影
            elevation: 0,
            // 设置为浮动模式
            floating: true,
            // 设置为固定模式
            pinned: false,
            // 设置展开高度
            expandedHeight: 200,
            flexibleSpace: FlexibleSpaceBar(
              background: Image.network(
                'https://example.com/image.jpg',
                fit: BoxFit.cover,
              ),
            ),
          ),
          SliverList(
            delegate: SliverChildBuilderDelegate(
              (BuildContext context, int index) {
                return ListTile(
                  title: Text('Item $index'),
                );
              },
              childCount: 100,
            ),
          ),
        ],
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: ScrollPage(),
  ));
}