keep-alive,activated,deactivated

Original link: https://www.jianshu.com/p/0272c0fe9392
Key points:
1. When a component is switched inside, its two life cycle hook functions, activated and deactivated, will be executed accordingly.
2. The access assembly performs a activated executed, execution leaves Deactivated
components within 3.keep-alive, (cached components), it is first loaded only once created and mouted