The life cycle of react components

React rendercomponent ()

1. Mounted

The component is generated by the render parsing of the corresponding DOM node and is inserted into a process in the browser's DOM structure. (See effect)

2. Update

The process of a mounted component being re-render. SetState () or setprops ()----render ()

3. Unmounted---react.unmountandreleasereactrootnode ()

The process by which a mounted component corresponds to a DOM node that is removed from the DOM structure.

The react of each state encapsulates the corresponding hook function. (Once a hook event occurs, the program that hooks the event will receive the system when a hook is made to a particular system event.)

Notification, the program can respond in the first time)