460d55e659
Prep for https://github.com/flutter/flutter/issues/178827 This bumps Dart to 3.9. We are holding off on 3.10 until we can include best practices for dot shorthands in the style guide, which will follow the lint update in #178827 ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
Flutter API reference documentation
Flutter is Google's SDK for crafting beautiful, fast user experiences for mobile, web, and desktop from a single codebase. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
This API reference 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:
- Install Flutter
- Flutter documentation
- Stable channel API reference documentation
- Main channel API reference documentation
- Contributing to Flutter
Offline Documentation
In addition to the online sites above, Flutter's documentation can be downloaded as an HTML documentation ZIP file for use when offline or when you have a poor internet connection.
Note
The offline documentation files are quite large, approximately 300MB zipped, 1GB unzipped.
Offline HTML documentation ZIP bundles:
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- Stable channel Zeal XML configuration URL: https://api.flutter.dev/offline/flutter.xml
- Main channel Zeal XML configuration URL: https://main-api.flutter.dev/offline/flutter.xml
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:
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:
import 'dart:async';
import 'dart:ui';
Except for 'dart:core', you must import a Dart library before you can use it.
Supporting 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:
import 'package:flutter_test/flutter_test.dart';
import 'package:file/local.dart';
Packages on pub.dev
Flutter has a rich ecosystem of packages that have been contributed by the Flutter team and the broader open source community to a central repository. Among the thousands of packages, you'll find support for Firebase, Google Fonts, hardware services like Bluetooth and camera, new widgets and animations, and integration with other popular web services. You can browse those packages at pub.dev.