1.打开终端输入：git clone https://github.com/facebook/react-native.git下载完成后，在
QQ20160919-0.png
目录中存在下载后的相关文件。
2.终端输入：cd react-native && npm install
出现提示，npm command no found 因为你的mac中 npm没有安装
npm是什么？
<li>�NPM的全称是Node Package Manager ，是一个NodeJS包管理和分发工具，已经成为了非官方的发布Node模块（包）的标准<li>
如何安装npm呢？
一：如果你安装了Homebrew
如何安装Homebrew见这里：http://brew.sh/index_zh-cn.html
直接使用命令：
brew install node
二：直接从官网上下载安装
点击进入网址，https://nodejs.org/en/#download
QQ20160919-1.png
点击下载“Current”,下载完成后执行*.pkg安装完成即可。
安装完成后，就可以运行React-Native Examples下的demo了。
ps:如果通过终端命令下载不成功或是下载50%重新下载的导致下载的下载两次的如下图所示：
QQ20160919-2.png
则需要删除目录中的react-native，否则运行demo时会出现如下错误
Failed to build DependencyGraph: @providesModule naming collision:
Duplicate module name: AppEventsTest
Paths: /Users/Founder/react-native/react-native/IntegrationTests/AppEventsTest.js collides with /Users/Founder/react-native/IntegrationTests/AppEventsTest.js
This error is caused by a @providesModule declaration with the same name across two different files.
Error: @providesModule naming collision:
Duplicate module name: AppEventsTest
Paths: /Users/Founder/react-native/react-native/IntegrationTests/AppEventsTest.js collides with /Users/Founder/react-native/IntegrationTests/AppEventsTest.js
This error is caused by a @providesModule declaration with the same name across two different files.
at HasteMap._updateHasteMap (/Users/Founder/react-native/packager/react-packager/src/node-haste/DependencyGraph/HasteMap.js:155:13)
at module.getName.then.name (/Users/Founder/react-native/packager/react-packager/src/node-haste/DependencyGraph/HasteMap.js:115:31)
Process terminated. Press <enter> to close the window
如上述步骤，React-Native的demo就可以运行起来了。
参考文档：facebook_github
