mac flutter 创建过程及遇到的问题
参考：
1.入门: 在macOS上搭建Flutter开发环境 系统要求
1.打开终端
2.clone flutter
命令：
git clone -b beta https://github.com/flutter/flutter.git
3.打开(或创建) .bash_profile
1.打开
终端输入：
open -e ~/.bash_profile
如果不能成功打开，那就创建
2.创建
1.进入当前用户的home目录（默认就是）
cd ~ 或
cd /Users/用户名
4.更新环境变量
打开bash_profile就是为了可以永久的更新环境变量，一劳永逸。请看解释和注意后根据自己的需要来将代码添加到打开的bash_profile。
export PUB_HOSTED_URL=https://pub.flutter-io.cn export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn
解释： 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。你也可以不设置，如果你能FQ的话。如果不能的话可以直接复制上面的代码
export PATH= PATH_TO_FLUTTER_GIT_DIRECTORY/flutter/bin:$PATH
注意：PATH_TO_FLUTTER_GIT_DIRECTORY 为你flutter的路径，比如在当前用户路径里。如果不确定，可以点击mac上面菜单的"前往" --> "个人"，然后在此文件夹里找是否有flutter文件夹。如果有的话你的应该这样写:
export PATH= /Users/用户名/flutter/bin:$PATH
然后输入以下命令更新刚刚配置的环境变量:
source .bash_profile
然后输入以下命令，通过运行flutter/bin命令验证目录是否在已经在PATH中:
echo $PATH
如果看到有flutter那就是配置好了
注意: 如果你使用终端是zsh，终端启动时 ~/.bash_profile 将不会被加载，解决办法就是修改 ～/.zshrc ，在其中添加：source ～/.bash_profile
5.运行 flutter doctor
输入下面这个命令，来看还有没有要安装的依赖项：
flutter doctor
我的话一开始是这个
让我更新flutter，我不想看到warning所以立马更新了。
flutter upgrade
错误1：
然后就看x了，这是我第一个打叉的地方
[✗] Android toolchain - develop for Android devices ✗ Unable to locate Android SDK. Install Android Studio from: https://developer.android.com/studio/index.html On first launch it will assist you in installing the Android SDK components. (or visit https://flutter.io/setup/#android-setup for detailed instructions). If Android SDK has been installed to a custom location, set $ANDROID_HOME to that location.
这是让我安装android studio并且设置好$ANDROID_HOME这个环境变量。
于是我便按照提示打开https://developer.android.com/studio/index.html，并且下载安装了android studio。
安装后最好运行一下android studio，好安装andriod sdk。运行好根据界面提示点下一步，如果没有sdk会提示安装，只要点就行了。记得查看下安装路径，一般路径都是在当前用户的Library文件夹里。
安装好sdk后，可以把android studio关了。
然后打开bash_profile
open -e .bash_profile
在bash_profile里加上
export ANDROID_HOME="/Users/用户名/Library/Android/sdk" //android sdk目录，替换为你自己的 export PATH=${PATH}:${ANDROID_HOME}/tools export PATH=${PATH}:${ANDROID_HOME}/platform-tools
更新配置
source .bash_profile
然后运行
flutter doctor
看这一项还报错不。ok还是有报错，报错如下：
[!] Android toolchain - develop for Android devices (Android SDK 28.0.2)
✗ Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
根据提示运行：
flutter doctor --android-licenses
然后根据提示一直y，y到结束为止。
错误2：
这是我第二个打叉的地方
[!] iOS toolchain - develop for iOS devices
✗ Xcode installation is incomplete; a full installation is necessary for iOS development.
Download at: https://developer.apple.com/xcode/download/
Or install Xcode via the App Store.
Once installed, run:
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
✗ libimobiledevice and ideviceinstaller are not installed. To install, run:
brew install --HEAD libimobiledevice
brew install ideviceinstaller
✗ ios-deploy not installed. To install:
brew install ios-deploy
✗ CocoaPods not installed.
CocoaPods is used to retrieve the iOS platform side's plugin code that responds to your plugin usage on the Dart side.
Without resolving iOS dependencies with CocoaPods, plugins will not work on iOS.
For more info, see https://flutter.io/platform-plugins
To install:
brew install cocoapods
pod setup
依旧是根据提示，我去App Store安装了xcode。
安装好后根据之前的错误信息运行：
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
然后：
brew install --HEAD libimobiledevice brew install ideviceinstaller brew install ios-deploy brew install cocoapods pod setup
进行到这我报错了：
[!] /usr/bin/git clone https://github.com/CocoaPods/Specs.git master --progress
Cloning into 'master'...
remote: Counting objects: 2353094, done.
remote: Compressing objects: 100% (450/450), done.
error: RPC failed; curl 18 transfer closed with outstanding read data remaining
fatal: The remote end hung up unexpectedly
fatal: early EOF
fatal: index-pack failed
弄个加速器就可以了。我用的云墙netfits，有试用，试用够下载了。如果有更好的加速器欢迎留言。
再运行doctor
flutter doctor
ios还有报错：
[!] iOS toolchain - develop for iOS devices (Xcode 9.4.1)
✗ Missing Xcode dependency: Python module "six".
Install via 'pip install six' or 'sudo easy_install six'.
按照提示输入'pip install six' 或 'sudo easy_install six'。然后再运行doctor，我这里ios没有报错了。就剩错误3里的报错。
错误3：
[✓] Android Studio (version 3.1)
✗ Flutter plugin not installed; this adds Flutter specific functionality.
✗ Dart plugin not installed; this adds Dart specific functionality.
android studio里还少了两个插件。我们打开andriod studio。
1.点击preferences
2.搜索plugins
4.点击安装
有弹框提示要安装dart，同意。等安装好后重启andriod studio。
错误4
[!] Xcode - develop for iOS and macOS (Xcode 11.2.1)
✗ CocoaPods not installed.
CocoaPods is used to retrieve the iOS and macOS platform side's plugin
code that responds to your plugin usage on the Dart side.
Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/platform-plugins
To install:
sudo gem install cocoapods
根据提示输入一下命令：
sudo gem install cocoapods
1.安装dart（官网）
brew tap dart-lang/dart
brew install dart
