Open hhstore opened 3 years ago
null safety
是好事, 问题是, 代码要全部改一遍. 您倒是把 transfer 工具搞好, 再放炮仗好吧. shit.a!.b
这种语法判空. 如果是 bool 型, 就会遇到 !a!.b
这种搞笑写法. rust
特性, 能不能走点心. 满屏都是这个 !
判断, 傻逼到没朋友. 符号学
大师吗? WTF.pubspec.yaml
文件,将最低 SDK 版本设置到 2.12.0:
environment:
sdk: '>=2.12.0 <3.0.0'
// @dart=2.9
import 'src/my_app.dart';
main() {
//...
}
dart pub outdated --mode=null-safety
flutter pub get
dart pub outdated --mode=null-safety
# 升级包:
dart pub upgrade --null-safety
dart migrate
environment:
sdk: '>=2.12.0 <3.0.0'
flutter run --no-sound-null-safety
当前版本:
-> % fvm flutter --version
Flutter 1.22.5 • channel unknown • unknown source
Framework • revision 7891006299 (4 个月前) • 2020-12-10 11:54:40 -0800
Engine • revision ae90085a84
Tools • Dart 2.10.4
已 release 的 2.0 版本情况:
-> % fvm releases
--------------------------------------
Mar 13 21 │ 2.1.0-12.1.pre dev
--------------------------------------
Mar 15 21 │ 2.0.2
--------------------------------------
Mar 18 21 │ 2.1.0-12.2.pre beta
--------------------------------------
--------------------------------------
Mar 19 21 │ 2.0.3 stable
--------------------------------------
安装 2.0.3 版本:
-> % fvm install 2.0.3
Installing version: 2.0.3
正克隆到 '/Users/henry/.fvm/versions/2.0.3'...
remote: Enumerating objects: 286668, done.
remote: Total 286668 (delta 0), reused 0 (delta 0), pack-reused 286668
接收对象中: 100% (286668/286668), 131.79 MiB | 643.00 KiB/s, 完成.
处理 delta 中: 100% (220856/220856), 完成.
Version installed: 2.0.3
Downloading Dart SDK from Flutter engine 3459eb24361807fb186953a864cf890fa8e9d26a...
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 195M 100 195M 0 0 10.8M 0 0:00:17 0:00:17 --:--:-- 10.6M
Building flutter tool...
Flutter 2.0.3 • channel unknown • unknown source
Framework • revision 4d7946a68d (11 天前) • 2021-03-18 17:24:33 -0700
Engine • revision 3459eb2436
Tools • Dart 2.12.2
项目切换到 2.0 版本:
-> % fvm use 2.0.3 --global
The global Flutter version is now 2.0.3
Make sure to add /Users/henry/.fvm/default/bin to your PATH environment variable
Project now uses Flutter: 2.0.3
___________________________________________________
FVM Update Available 1.3.7 → 1.3.8
Changelog: https://pub.dev/packages/fvm/changelog
Run pub global activate fvm to update
___________________________________________________
项目内切换 2.0 版本:
fvm use 2.0.3
# 确认切换成功:
fvm flutter --version
Flutter 2.0.3 • channel unknown • unknown source
Framework • revision 4d7946a68d (11 天前) • 2021-03-18 17:24:33 -0700
Engine • revision 3459eb2436
Tools • Dart 2.12.2
升级 fvm 工具:
pub global activate fvm
pubspec.yaml
设置包的 dart 版本最低要求: environment:
sdk: '>=2.12.0 <3.0.0'
flutter: ">=2.0.0"
null safety
标记.
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