Flutter 应用入门：包管理

pubspec.yaml

name: flutter_combat
description: A Flutter combat 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.
# 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: ">=2.1.0 <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
  english_words: ^3.1.5

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:
  #  - images/a_dot_burr.jpeg
  #  - 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

解读

1. name：应用或包名称。
2. description: 应用或包的描述、简介。
3. version：应用或包的版本号。
4. dependencies：应用或包依赖的其它包或插件。
5. dev_dependencies：开发环境依赖的工具包（而不是flutter应用本身依赖的包）。
6. flutter：flutter相关的配置选项。

使用

import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';

class RandomWordsWidget extends StatelessWidget {
  Widget build(BuildContext context) {
    // 生成随机字符串
    final wordPair = WordPair.random();
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: Text(wordPair.toString()),
    );
  }
}

其他依赖方法

除了可以依赖Pub仓库，还可以依赖本地包和git仓库。

1. 依赖本地包

如果我们正在本地开发一个包，包名为pkg1，我们可以通过下面方式依赖：
dependencies:
    pkg1:
        path: ../../code/pkg1
路径可以是相对的，也可以是绝对的。

2. 依赖Git

也可以依赖存储在Git仓库中的包。如果软件包位于仓库的根目录中，请使用以下语法
dependencies:
  pkg1:
    git:
      url: git://github.com/xxx/pkg1.git
上面假定包位于Git存储库的根目录中。如果不是这种情况，可以使用path参数指定相对位置，例如：
dependencies:
  package1:
    git:
      url: git://github.com/flutter/packages.git
      path: packages/package1