futter软件包获取未安装http软件包

Question

我是flutter的新手，当我使用flutter软件包时，它会持续4秒钟回答命令，但是当我查看.packages归档文件时，并没有下载所有软件包。还有其他下载软件包的方法吗？ pub get做同样的事情。 这是pubspec.yaml

name: flutter_app
description: A new Flutter application.

# 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.
# Read more about versioning at semver.org.
  version: 1.0.0+1

 environment:
  sdk: ">=2.0.0-dev.68.0 <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: ^0.1.2
    http: ^0.12.0

  dev_dependencies:
   flutter_test:
   sdk: flutter

我的一个朋友做了同样的事情，但是下载软件包没有问题