Ubuntu 16.04 下 React Native环境搭建

摘要：安装此工具可以提高开发时的性能可以快速捕捉文件的变化从而实现实时刷新是一个静态的类型检查工具，这一语法并不属于标准，只是自家的代码规范。

转载请注明出处：http://www.wangxinarhat.com/2016/05/21/2016-05-21-react-native1/
摸索React Native有一段时间了，尝试在Windows下和linux下搭建开发环境，踩过的坑还是会忘，在此记录

nodejs

sudo apt-get install -y build-essential
curl -sL https://deb.nodesource.com/setup_4.x | sudo -E bash -
sudo apt-get install -y nodejs
sudo ln -s /usr/bin/nodejs /usr/bin/node

React Native命令工具

npm install -g react-native-cli

Watchman
Watchman是由Facebook提供的监视文件系统变更的工具。安装此工具可以提高开发时的性能（packager可以快速捕捉文件的变化从而实现实时刷新）

git clone https://github.com/facebook/watchman.git
cd watchman
git checkout v4.5.0
./autogen.sh
./configure
make
sudo make install

Flow
Flow是一个静态的JS类型检查工具，这一语法并不属于ES标准，只是Facebook自家的代码规范。

npm install -g flow-bin

将ANDROID_HOME环境变量指向Android SDK的路径,ANDROID_NDK指向NDK目录

具体的做法是把下面的命令加入到~/.bashrc、~/.bash_profile文件中

export ANDROID_HOME=~/Android/Sdk
export ANDROID_NDK=~/Android/android-ndk-r10e

使用下列命令使其立即生效（否则重启后才生效）：
source ./bash_profile

初始化一个React Native的Hello World项目并运行

react-native init HelloReact
cd HelloReact
react-native run-android

正常的话这是该有一个这样的界面

修改下index.android.js文件，手机端reload js，体验React Native

运行react-native run-android后手机出现Could not connect to development server

如下图：

查看github找到一个issue，解决方法是：
A common issue is that the packager is not started automatically when you run react-native run-android. You can start it manually using:

就是说运行react-native run-android，Packger可能不会自动运行，需手动启动它
react-native start

watchman issue : Poison: inotify_add_watch
出现以下错误

ERROR  A non-recoverable condition has triggered.  Watchman needs your help!
The triggering condition was at timestamp=1466189741: inotify-add-watch(/home/wangxinarhat/ReactProjects/HelloReact/node_modules/react-native/node_modules/fbjs-scripts/node_modules/babel/node_modules/chokidar/node_modules/anymatch/node_modules/micromatch/node_modules/braces/node_modules) -> The user limit on the total number of inotify watches was reached; increase the fs.inotify.max_user_watches sysctl
All requests will continue to fail with this message until you resolve
the underlying problem.  You will find more information on fixing this at
https://facebook.github.io/watchman/docs/troubleshooting.html#poison-inotify-add-watch

{"watchmanResponse":{"version":"4.1.0","error":"A non-recoverable condition has triggered.  Watchman needs your help!
The triggering condition was at timestamp=1466189741: inotify-add-watch(/home/wangxinarhat/ReactProjects/HelloReact/node_modules/react-native/node_modules/fbjs-scripts/node_modules/babel/node_modules/chokidar/node_modules/anymatch/node_modules/micromatch/node_modules/braces/node_modules) -> The user limit on the total number of inotify watches was reached; increase the fs.inotify.max_user_watches sysctl
All requests will continue to fail with this message until you resolve
the underlying problem.  You will find more information on fixing this at
https://facebook.github.io/watchman/docs/troubleshooting.html#poison-inotify-add-watch
"}}
Error: A non-recoverable condition has triggered.  Watchman needs your help!
The triggering condition was at timestamp=1466189741: inotify-add-watch(/home/wangxinarhat/ReactProjects/HelloReact/node_modules/react-native/node_modules/fbjs-scripts/node_modules/babel/node_modules/chokidar/node_modules/anymatch/node_modules/micromatch/node_modules/braces/node_modules) -> The user limit on the total number of inotify watches was reached; increase the fs.inotify.max_user_watches sysctl
All requests will continue to fail with this message until you resolve
the underlying problem.  You will find more information on fixing this at
https://facebook.github.io/watchman/docs/troubleshooting.html#poison-inotify-add-watch

    at ChildProcess. (/home/wangxinarhat/ReactProjects/HelloReact/node_modules/react-native/node_modules/sane/node_modules/fb-watchman/index.js:206:21)
    at emitTwo (events.js:87:13)
    at ChildProcess.emit (events.js:172:7)
    at maybeClose (internal/child_process.js:827:16)
    at Socket. (internal/child_process.js:319:11)
    at emitOne (events.js:77:13)
    at Socket.emit (events.js:169:7)
    at Pipe._onclose (net.js:477:12)

因为inotify默认内核参数值太小，修改之：

echo 256 | sudo tee -a /proc/sys/fs/inotify/max_user_instances
echo 32768 | sudo tee -a /proc/sys/fs/inotify/max_queued_events
echo 65536 | sudo tee -a /proc/sys/fs/inotify/max_user_watches
watchman shutdown-server