nested_scroll_view.1.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flutter code sample for NestedScrollView

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,
      home: MyStatelessWidget(),
    );
  }
}

class MyStatelessWidget extends StatelessWidget {
  const MyStatelessWidget({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: NestedScrollView(
            // Setting floatHeaderSlivers to true is required in order to float
            // the outer slivers over the inner scrollable.
            floatHeaderSlivers: true,
            headerSliverBuilder:
                (BuildContext context, bool innerBoxIsScrolled) {
              return <Widget>[
                SliverAppBar(
                  title: const Text('Floating Nested SliverAppBar'),
                  floating: true,
                  expandedHeight: 200.0,
                  forceElevated: innerBoxIsScrolled,
                ),
              ];
            },
            body: ListView.builder(
                padding: const EdgeInsets.all(8),
                itemCount: 30,
                itemBuilder: (BuildContext context, int index) {
                  return SizedBox(
                    height: 50,
                    child: Center(child: Text('Item $index')),
                  );
                })));
  }
}