最新版本的火焰是否支持零安全？

Question

我对火焰游戏引擎很陌生，但是每当我尝试运行我的程序时，它总是说

错误：无法以可靠的 null 安全性运行，因为以下依赖项 不支持空安全：

• 包装：火焰
• package:ordered_set
• 包：box2d_flame

我只是想知道我是否没有使用最新版本的火焰，或者我是否需要暂时禁用空安全？这是我的 pubspec.yaml 文件当前的样子。

name: first_game
description: A new Flutter project.

# The following line prevents the package from being accidentally published to
# pub.dev using `pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.12.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter


  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.2
  shared_preferences: ^2.0.5
  flame: ^0.29.4


dev_dependencies:
  flutter_test:
    sdk: flutter

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  assets:
     - assets/images/terrythemale.png
  #   - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages

Answer 1

这是当前的稳定版本，我们的最新版本是 1.0.0-rc10，我们确实支持 null-safety（这也是我们所有文档的版本）。

但请注意，pub 计数 rc10 小于 rc9，因此您必须跳过 pubspec 文件中的 ^ 并专门依赖于 rc10，如下所示：

dependencies:
  ...
  flame: 1.0.0-rc10

我们很可能会在今天晚些时候发布不会出现此问题的 rc11。

编辑：rc11 现已发布，所以现在您可以再次使用 ^：

dependencies:
  ...
  flame: "^1.0.0-releasecandidate.11"

Answer 2

基于您使用的版本的 pubspec：https://github.com/flame-engine/flame/blob/0.29.3/pubspec.yaml

environment:
  sdk: ">=2.3.0 <3.0.0"
  flutter: ">=1.6.0"

答案是否定的。但是有一个候选版本（最新的 1.0.0-rc10）似乎支持空安全：https://github.com/flame-engine/flame/blob/1.0.0-rc10/packages/flame/pubspec.yaml

environment:
  sdk: ">=2.12.0 <3.0.0"
  flutter: ">=1.24.0"

因此，您可以等待“1.0.0”发布或使用候选发布版。

Answer 3

从错误来看，我也无法在火焰 v0.29.4 的发布文档中找到健全的空安全性的提及，我认为它仍然没有迁移到空安全性。

您在 pubspec.yaml 中的最小 sdk 版本是 2.12，这使您的应用程序默认使用健全的空安全性，因此构建项目时使用带有颤振 /dart 命令的标志 --no-sound-null-safety 例如。 “$ flutter run --no-sound-null-safety”。更多信息请访问https://dart.dev/null-safety/unsound-null-safety。

Answer 4

迁移你的 flutter dart 包，因为现在一切都是关于 null 安全性的

所以在更新flutter（版本sdk 2.0.2）后，它只允许空安全插件。

一一遵循这些迁移命令。

第 1 步）

dart migrate

如果您的迁移失败。所以，这背后会有一些原因，比如， 一些颤振插件没有升级。 或者某个插件依赖于其他一些非空安全插件。

第 2 步）

flutter pub outdated --mode=null-safety

通过使用此命令，您可以查看最新的包版本/具有空安全性的插件。从这里您可以更新插件版本。

步骤 3) 再次运行此命令

dart migrate

第 4 步）

flutter pub upgrade

第 5 步）

flutter pub get

第 6 步）

flutter run

Using this link more idea

https://youtu.be/eBr5tlumwlg