Flutter 2：国际空安全库中的问题

Question

我将我的 flutter sdk 升级到 flutter 2.0.0。更新 sdk 后，我几乎将所有库都更改为空安全版本：

environment:
  sdk: '>=2.12.0 <3.0.0'

dependencies:
  flutter:
    sdk: flutter
  flutter_localizations:
    sdk: flutter 
  cupertino_icons: ^0.1.3
  encrypt: ^4.1.0
  flutter_hooks: ^0.15.0
  flutter_map: ^0.11.0
  flutter_password_strength: ^0.1.5
  flutter_svg: ^0.18.0
  geolocator: ^7.0.1
  get: ^3.25.6
  get_it: ^6.0.0
  injectable: ^1.1.2
  local_auth: ^1.1.0
  moor_flutter: ^3.1.0
  provider: ^5.0.0
  shared_preferences: ^2.0.3
  supercharged: ^1.12.0
  intl: ^0.17.0

更新运行 dart $ dart migrate 命令后。但它显示了有关 intl 插件的这些问题：

Analyzing project...
[---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------/]
5 analysis issues found:
  error • A value of type 'Null' can't be returned from the function '_findExact' because it has a return type of 'MessageLookupByLibrary' at lib/generated/intl/messages_all.dart:34:14 • (return_of_invalid_type)
  error • A value of type 'Null' can't be returned from the function '_findGeneratedMessagesFor' because it has a return type of 'MessageLookupByLibrary' at lib/generated/intl/messages_all.dart:65:36 • (return_of_invalid_type)
  error • Non-nullable instance field 'current' must be initialized at lib/generated/l10n.dart:16:3 • (not_initialized_non_nullable_instance_field)
  error • The non-nullable variable 'current' must be initialized at lib/generated/l10n.dart:18:12 • (not_initialized_non_nullable_variable)
  error • A value of type 'S?' can't be returned from the method 'of' because it has a return type of 'S' at lib/generated/l10n.dart:35:12 • (return_of_invalid_type)

The migration tool didn't start, due to analysis errors.

我使用的是最新版本的 intl 吗？我该如何解决？

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.0.0, on Linux, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.0-rc1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 4.0)
[✓] VS Code (version 1.53.2)
[✓] Connected device (2 available)

• No issues found!

Answer 1

我遇到了同样的问题。以下是解决此问题的 3 个步骤：

首先，将pubspec.yaml中的intl依赖更新为：

国际：0.17.0-nullsafety.2
如果还是不行，再在根目录中添加这2个字段。

dependency_overrides: 国际：0.17.0-nullsafety.2
生成也可以通过 Android Studio 中的插件进行。我使用旧的 (v 0.12)，在我更新到 (v 0.14) 后，它开始生成用于本地化的空安全飞镖文件。

我想我踩到了这里的每一块石头。

Flutter 2：国际空安全库中的问题

Flutter 2: problem in Intl null safety library

migration

flutter

dart-null-safety