| layout | title | permalink |
|---|---|---|
page |
AppBar Basics |
/catalog/samples/basic-app-bar/ |
A typical AppBar with a title, actions, and an overflow dropdown menu.
Android screenshot
An app that displays one of a half dozen choices with an icon and a title. The two most common choices are available as action buttons and the remaining choices are included in the overflow dropdow menu.
Try this app out by creating a new project with flutter create and replacing the contents of lib/main.dart with the code that follows.
// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/material.dart';
// This app is a stateful, it tracks the user's current choice.
class BasicAppBarSample extends StatefulWidget {
@override
_BasicAppBarSampleState createState() => new _BasicAppBarSampleState();
}
class _BasicAppBarSampleState extends State<BasicAppBarSample> {
Choice _selectedChoice = choices[0]; // The app's "state".
void _select(Choice choice) {
// Causes the app to rebuild with the new _selectedChoice.
setState(() {
_selectedChoice = choice;
});
}
@override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
appBar: new AppBar(
title: const Text('Basic AppBar'),
actions: <Widget>[
// action button
new IconButton(
icon: new Icon(choices[0].icon),
onPressed: () {
_select(choices[0]);
},
),
// action button
new IconButton(
icon: new Icon(choices[1].icon),
onPressed: () {
_select(choices[1]);
},
),
// overflow menu
new PopupMenuButton<Choice>(
onSelected: _select,
itemBuilder: (BuildContext context) {
return choices.skip(2).map((Choice choice) {
return new PopupMenuItem<Choice>(
value: choice,
child: new Text(choice.title),
);
}).toList();
},
),
],
),
body: new Padding(
padding: const EdgeInsets.all(16.0),
child: new ChoiceCard(choice: _selectedChoice),
),
),
);
}
}
class Choice {
const Choice({this.title, this.icon});
final String title;
final IconData icon;
}
const List<Choice> choices = const <Choice>[
const Choice(title: 'Car', icon: Icons.directions_car),
const Choice(title: 'Bicycle', icon: Icons.directions_bike),
const Choice(title: 'Boat', icon: Icons.directions_boat),
const Choice(title: 'Bus', icon: Icons.directions_bus),
const Choice(title: 'Train', icon: Icons.directions_railway),
const Choice(title: 'Walk', icon: Icons.directions_walk),
];
class ChoiceCard extends StatelessWidget {
const ChoiceCard({Key key, this.choice}) : super(key: key);
final Choice choice;
@override
Widget build(BuildContext context) {
final TextStyle textStyle = Theme.of(context).textTheme.display1;
return new Card(
color: Colors.white,
child: new Center(
child: new Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Icon(choice.icon, size: 128.0, color: textStyle.color),
new Text(choice.title, style: textStyle),
],
),
),
);
}
}
void main() {
runApp(new BasicAppBarSample());
}