In this example, we deal below queries.
How to create a SliverAppBar?
How to add a ListView to SliverAppBar?
How to automatically adjust the text color in SliverAppBar when collapsed?
Here is the final output of this program.
![](http://www.fluttercentral.com/Uploads/eece1105-70ae-4655-9129-0cef283597ce.gif)
Here is the final code from main.dart. All you need to do is, copy paste this code into your newly created flutter project and run.
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or press Run > Flutter Hot Reload in IntelliJ). Notice that the
// counter didn't reset back to zero; the application is not restarted.
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => new _MyHomePageState();
}
ScrollController _controller;
class _MyHomePageState extends State<MyHomePage> {
@override
void initState() {
_controller = ScrollController();
_controller.addListener(_scrollListener);
super.initState();
}
Color clr = Colors.lightGreen;
_scrollListener() {
if (_controller.offset > _controller.position.minScrollExtent &&
!_controller.position.outOfRange) {
setState(() {
clr = Colors.red;
});
}
if (_controller.offset <= _controller.position.minScrollExtent &&
!_controller.position.outOfRange) {
setState(() {
clr = Colors.lightGreen;
});
}
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return new Scaffold(
appBar: new AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: new Text("Hello"),
),
body: new Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child:
new Container(
child:
CustomScrollView(
controller: _controller,
slivers: <Widget>[
SliverAppBar(
pinned: true,
expandedHeight: 250.0,
flexibleSpace: FlexibleSpaceBar(
title: Text("Demo",
style: const TextStyle(
fontSize: 10.0,
fontWeight: FontWeight.w900,
color: Colors.green,
)),
background: FlutterLogo(
size: 20.0,
colors: Colors.blue,
),
),
backgroundColor: clr,
),
SliverFixedExtentList(
itemExtent: 50.0,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Container(
alignment: Alignment.center,
color: Colors.lightBlue[100 * (index % 9)],
child: Text('list item $index'),
);
},
childCount: 50,
),
),
],
),
),
),
);
}
}
Hope this is helpful.
Thanks,
Srikanth