下载Flutter

https://flutter.io/docs/development/tools/sdk/archive

在这里获取Flutter的安装包，推荐使用stable channel的安装包。下载完成后解压。

设置环境变量

可以在~/.bash_profile里设置：

export PATH="$你的解压目录/flutter/bin:$PATH"
export PUB_HOSTED_URL=https://pub.flutter-io.cn   # 国内用户需要设置
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn  # 国内用户需要设置
export PATH=PATH_TO_FLUTTER_GIT_DIRECTORY/flutter/bin:$PATH

然后

source .bash_profile

Flutter命令

doctor可以检测当前开发环境

flutter doctor

运行结果如下：
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, v1.0.0, on Mac OS X 10.13.6 17G65, locale zh-Hans-CN)
[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
[✓] iOS toolchain - develop for iOS devices (Xcode 10.1)
[✓] Android Studio (version 3.3)
[!] IntelliJ IDEA Ultimate Edition (version 2018.1.1)
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
[✓] VS Code (version 1.30.1)
[✓] Connected device (2 available)

! Doctor found issues in 1 category.

channel可以更改flutter的分支

# 切换到beta分支
flutter channel beta 

# 切换到stable分支
flutter channel stable

运行结果如下：
Switching to flutter channel 'stable'...
git: 来自 https://github.com/flutter/flutter
git:    7eb11aac5..789376b83  master     -> origin/master
git: 已经位于 'stable'
git: 您的分支与上游分支 'origin/stable' 一致。