摘要
整理组件加载过程,详细见官方文档:https://facebook.github.io/react/docs/react-component.html
mount 过程
1)constructor
2)componentWillMount
3)render
4)componentDidMount
update
1)componentWillReceiveProps
2)shouldComponentUpdate
3)componentWillUpdate
4)render
5)componentDidUpdate
unmount 过程
1)componentWillUnMount