系统要求
要安装并运行Flutter，您的开发环境必须满足以下最低要求:
- 操作系统: macOS (64-bit)；
- 磁盘空间: 700 MB (不包括Xcode或Android Studio的磁盘空间）；
- 工具: Flutter 依赖下面这些命令行工具；
bash, mkdir, rm, git, curl, unzip, which
获取Flutter SDK
要获得Flutter，请先使用git克隆Flutter，然后将该flutter工具添加到您的用户路径。
如果这是您第一次在此机器上安装Flutter，请克隆beta分支，然后将该flutter工具添加到您的系统路径中:
git clone -b beta https://github.com/flutter/flutter.git
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=`pwd`/flutter/bin:$PATH
注意： 以上配置命令为当前终端窗口临时设置PATH变量，你会发现系统重新启动后配置的PATH变量丢失，在终端执行flutter doctor 提示command not found 。所以我们要将Flutter PATH环境变量永久添加到系统路径中，以便可以运行flutter命令在任何终端会话中。
具体步骤如下：
1.确定您Flutter SDK的目录，您将在步骤3中用到；
2.在终端打开(或创建) $HOME/.bash_profile. 文件路径和文件名可能在您的机器上不同；
3.添加以下行并更改[PATH_TO_FLUTTER_GIT_DIRECTORY]为克隆Flutter的git repo的路径；
下面贴一个笔者本机(mac)的环境变量配置
//Android sdk 环境变量配置（没配置的需要配置）
export ANDROID_HOME="/Users/geek/Library/Android/sdk"
export PATH=${PATH}:${ANDROID_HOME}/tools
export PATH=${PATH}:${ANDROID_HOME}/platform-tools
//Flutter sdk 环境变量配置
export PUB_HOSTED_URL=https://pub.flutter-io.cn
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn
export PATH=/Users/geek/flutter/bin:$PATH
//注意说明：geek为我本机的用户名，配置时请替换为你自己本机的用户名；注意确认自己Flutter SDK本机路径；
注意： 由于一些flutter命令需要联网获取数据，如果您是在国内访问，由于众所周知的原因，直接访问很可能不会成功。 上面的PUB_HOSTED_URL和FLUTTER_STORAGE_BASE_URL是google为国内开发者搭建的临时镜像。
以上配置完成后执行以下命令：
//1.刷新当前终端窗口
source $HOME/.bash_profile
//2.查看Flutter配置是否已经在PATH环境变量
echo $PATH
运行 flutter doctor 显示您可能需要安装的剩余依赖项
sunnydeMacBook-Pro:cache geek$ flutter doctor
╔════════════════════════════════════════════════════════════════════════════╗
║ WARNING: your installation of Flutter is 74 days old. ║
║ ║
║ To update to the latest version, run "flutter upgrade". ║
╚════════════════════════════════════════════════════════════════════════════╝
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.5.1, on Mac OS X 10.11.6 15G20015, locale zh-Hans)
[!] Android toolchain - develop for Android devices (Android SDK 28.0.2)
! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
[!] iOS toolchain - develop for iOS devices (Xcode 8.2.1)
✗ Flutter requires a minimum Xcode version of 9.0.0.
Download the latest version or update via the Mac App Store.
✗ Brew not installed; use this to install tools for iOS device development.
Download brew at https://brew.sh/.
[✓] Android Studio (version 3.1)
[✓] IntelliJ IDEA Ultimate Edition (version 2018.2)
[!] Connected devices
! Doctor found issues in 3 categories.
一般的错误会是xcode或Android Studio版本太低、或者没有ANDROID_HOME环境变量等，请按照提示解决。本机执行flutter doctor命令后提示老版本，需更新至最新版本；
更新Flutter SDK 至最新版本
sunnydeMacBook-Pro:cache geek$ flutter upgrade
Upgrading Flutter from /Users/geek/flutter...
From https://github.com/flutter/flutter
01d6444..ef71d9d master -> origin/master
Already up-to-date.
Upgrading engine...
Already up-to-date.
Flutter 0.5.1 • channel beta • https://github.com/flutter/flutter.git
Framework • revision c7ea3ca377 (3 months ago) • 2018-05-29 21:07:33 +0200
Engine • revision 1ed25ca7b7
Tools • Dart 2.0.0-dev.58.0.flutter-f981f09760
Running flutter doctor...
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.5.1, on Mac OS X 10.11.6 15G20015, locale zh-Hans)
[!] Android toolchain - develop for Android devices (Android SDK 28.0.2)
! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
[!] iOS toolchain - develop for iOS devices (Xcode 8.2.1)
✗ Flutter requires a minimum Xcode version of 9.0.0.
Download the latest version or update via the Mac App Store.
✗ Brew not installed; use this to install tools for iOS device development.
Download brew at https://brew.sh/.
[✓] Android Studio (version 3.1)
[✓] IntelliJ IDEA Ultimate Edition (version 2018.2)
[!] Connected devices
! Doctor found issues in 3 categories.
遇到打开Android Studio的时候顶部的模拟器一直是loading状态，即使已经打开了模拟器。 运行flutter doctor 提示如下：
Waiting for another flutter command to release the startup lock
查了一下github的flutter issue 找到了解决方法，如下：
1、打开flutter的安装目录/bin/cache/ ；
2、删除lockfile文件（rm -rf lockfle）；
3、重启AndroidStudio；
Android Studio配置Flutter环境
- 启动Android Studio.
- 打开插件首选项 (Preferences>Plugins on macOS,File>Settings>Plugins on Windows & Linux).
- 选择 Browse repositories…, 选择 Flutter 插件并点击 install.
-
重启Android Studio后插件生效.
具体如下图所示：
1.png
配置Flutter SDK路径
2.png
配置Dart SDK路径
3.png
创建Flutter 工程
首次创建Flutter工程可能会有一个漫长的等待过程
4.png
完美运行第一个Flutter应用
调试状态下运行应用启动后右上角会有一个DEBUG的标志
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