text
stringlengths
1
474
image,
fit: BoxFit.cover,
);<code_end>
Create an Icon widget:
<code_start>Icon(
Icons.star,
color: Colors.red[500],
),<code_end>
<topic_end>
<topic_start>
3. Add the visible widget to the layout widget
All layout widgets have either of the following:Add the Text widget to the Center widget:
<code_start>const Center(
child: Text('Hello World'),
),<code_end>
<topic_end>
<topic_start>
4. Add the layout widget to the page
A Flutter app is itself a widget, and most widgets have a build()
method. Instantiating and returning a widget in the app’s build() method
displays the widget.<topic_end>
<topic_start>Material apps
For a Material app, you can use a Scaffold widget;
it provides a default banner, background color,
and has API for adding drawers, snack bars, and bottom sheets.
Then you can add the Center widget directly to the body
property for the home page.
<code_start>class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
const String appTitle = 'Flutter layout demo';
return MaterialApp(
title: appTitle,
home: Scaffold(
appBar: AppBar(
title: const Text(appTitle),
),
body: const Center(
child: Text('Hello World'),
),
),
);
}
}<code_end>
info Note
The Material library implements widgets that follow Material
Design principles. When designing your UI, you can exclusively use
widgets from the standard widgets library, or you can use
widgets from the Material library. You can mix widgets from both
libraries, you can customize existing widgets,
or you can build your own set of custom widgets.<topic_end>
<topic_start>Cupertino apps
To create a Cupertino app, use CupertinoApp and CupertinoPageScaffold widgets.Unlike Material, it doesn’t provide a default banner or background color.
You need to set these yourself.To add an iOS-styled navigation bar to the top of your app, add a
CupertinoNavigationBar widget to the navigationBar
property of your scaffold.
You can use the colors that CupertinoColors provides to
configure your widgets to match iOS design.To learn what other UI components you can add, check out the
Cupertino library.
<code_start>class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return const CupertinoApp(
title: 'Flutter layout demo',
theme: CupertinoThemeData(
brightness: Brightness.light,
primaryColor: CupertinoColors.systemBlue,
),
home: CupertinoPageScaffold(
navigationBar: CupertinoNavigationBar(
backgroundColor: CupertinoColors.systemGrey,
middle: Text('Flutter layout demo'),
),
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('Hello World'),
],
),
),
),
);
}
}<code_end>
info Note
The Cupertino library implements widgets that follow
Apple’s Human Interface Guidelines for iOS.
When designing your UI, you can use
widgets from the standard widgets library, or the Cupertino library.
You can mix widgets from both libraries, you can customize existing widgets,
or you can build your own set of custom widgets.<topic_end>
<topic_start>Non-Material apps
For a non-Material app, you can add the Center widget to the app’s
build() method:
<code_start>class MyApp extends StatelessWidget {
const MyApp({super.key});
@override