react-native 遇过的错误

react native:Expected a component class,got [Object Object ]

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null is not an object

在react native用到es6的时候初始化state应该在constructor ()内，而不是用getInitialState()

class Search extends Component {
  constructor () {
    super();
    this.state = {
      ....
    }
  }
  ...
}

• 初始化项目后执行react-native run-ios，构建失败：

Command failed: /usr/libexec/PlistBuddy -c Print:CFBundleIdentifier build/Build/Products/Debug-iphonesimulator/xxx.app/Info.plist
Print: Entry, ":CFBundleIdentifier", Does Not Exist

更换版本

删除node-modules文件夹，修改pakage.json文件，然后执行npm install。其中，pakage.json文件应该这么改：

测试版本：
"react": "16.0.0-alpha.12",
"react-native": "0.45.0"

切换成下面的版本就可以了：
"react": "16.0.0-alpha.6",
"react-native": "0.44.3"

react-native upgrade

xcrun: error: unable to find utility "instruments", not a developer tool or in PATH

解决方法：在 终端执行如下命令 sudo xcode-select -s /Applications/Xcode.app/Contents/Developer/

注意：前提是你已经安装了xcode

react native45版本开始后，新建应用会抛出UNpackage xxxx错误

原因是最新的RN无法下载到4个tar.gz文件，由于被墙的原因，所以要手动去下载，下载好后把下载好的四个文件放到路径：/Users/xxx/.rncache/下面，这四个文件的下载路径分别是：

https://codeload.github.com/facebook/folly/tar.gz/v2016.09.26.00
https://codeload.github.com/google/double-conversion/tar.gz/v1.1.5
https://codeload.github.com/google/glog/tar.gz/v0.3.4
https://github.com/react-native-community/boost-for-react-native/releases/download/v1.63.0-0/boost_1_63_0.tar.gz