| Welcome to the Flutter API reference documentation. |
| |
| Flutter is Google’s mobile UI framework for crafting high-quality native |
| interfaces on iOS and Android in record time. Flutter works with existing code, |
| is used by developers and organizations around the world, and is free and open |
| source. |
| |
| The API reference herein covers all libraries that are exported by the Flutter |
| SDK. |
| |
| ### More Documentation |
| |
| This site hosts Flutter's API documentation. Other documentation can be found at |
| the following locations: |
| |
| * [flutter.io](https://flutter.io/) (main site) |
| * [Installation](https://flutter.io/docs/get-started/install) |
| * [Codelabs](https://flutter.io/docs/codelabs) |
| * [Contributing to Flutter](https://github.com/flutter/flutter/blob/master/CONTRIBUTING.md) |
| |
| ### Importing a Library |
| |
| #### Framework Libraries |
| |
| Libraries in the "Libraries" section below (or in the left navigation) are part |
| of the core Flutter framework and are imported using |
| `'package:flutter/<library>.dart'`, like so: |
| |
| ```dart |
| import 'package:flutter/material.dart'; |
| import 'package:flutter/services.dart'; |
| ``` |
| |
| #### Dart Libraries |
| |
| Libraries in the "Dart" section exist in the `'dart:'` namespace and are imported |
| using `'dart:<library>'`, like so: |
| |
| ```dart |
| import 'dart:async'; |
| import 'dart:ui'; |
| ``` |
| |
| Except for `'dart:core'`, you must import a Dart library before you can use it. |
| |
| #### Other Libraries |
| |
| Libraries in other sections are supporting libraries that ship with Flutter. |
| They are organized by package and are imported using |
| `'package:<package>/<library>.dart'`, like so: |
| |
| ```dart |
| import 'package:flutter_test/flutter_test.dart'; |
| import 'package:file/local.dart'; |
| ``` |
| |
| ### Finding Other Libraries |
| |
| Flutter has a rich community of packages that have been contributed by the |
| open-source community. You can browse those packages at |
| [pub.dartlang.org](http://pub.dartlang.org/flutter) |