import 'package:flutter/material.dart';

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

class Demo extends StatelessWidget {
    @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: CustomScrollView(
          slivers: [
            SliverAppBar(
              pinned: true,
              expandedHeight: 200,
              title: const Text('Title'),
              actions: [IconButton(icon: Icon(Icons.more_horiz))],
              flexibleSpace: FlexibleSpaceBar(
                background: Padding(
                  padding: EdgeInsets.only(top: 100),
                  child: Semantics(
                    header: true,
                    child: const Text('Expanded title'),
                  ),
                ),
              ),
            ),
            SliverList(
              delegate: SliverChildListDelegate(
                [
                  for (var i = 0; i < 50; i++)
                    Container(
                      height: 200,
                      child: Center(child: Text('Text $i')),
                    ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}