Nested Lists

main.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: NestedScrollView(
          headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
            // These are the slivers that show up in the "outer" scroll view.
            return <Widget>[
              SliverAppBar(title: Text('Demo!')), 
              SliverFixedExtentList(
                itemExtent: 48.0,
                delegate:SliverChildBuilderDelegate(
                  (BuildContext context, int index) => ListTile(title: Text('Outer Item $index')),
                  childCount: 20,
                ),
              ),
            ];
          },
          // These are the boxes that show up in the "inner" scroll view.
          body: ListView.builder(
            padding: const EdgeInsets.all(8),
            itemCount: 20,
            itemBuilder: (BuildContext context, int index) => Container(
              color: Colors.cyan,
              height: 50,
              child: Center(child: Text('Inner Item $index')),
            ),
          ),
        ),
      )
    );
  }
}