生命周期

各个阶段生命周期钩子函数

一、组件嵌套时执行顺序

嵌套情况：祖组件 => 父组件 => 子组件

1.启动：

1. grand father beforeCreate

2. grand father created

3. grand father beforeMount

4. father beforeCreate

5. father created

6. father beforeMount

7. son beforeCreate

8. son created

9. son beforeMount

10. son mounted

11. father mounted

12. grand father mounted

2.卸载父组件：

1. grand father beforeUpdate

2. father beforeUnmount

3. son beforeUnmount

4. son unmounted

5. father unmounted

6. grand father updated

3.挂载父组件

1. grand father beforeUpdate

2. father beforeCreate

3. father created

4. father beforeMount

5. son beforeCreate

6. son created

7. son beforeMount

8. son mounted

9. father mounted

10. grand father updated

结论：beforeMount之后开始示例化子组件

在线验证：入口

二、<KeepAlive>的情况

1.初始化

2.切走

3.切回

结论：

• 挂载时，mounted后再activated

• 切走的时候先加载新组件，再缓存旧组件：不执行unmount相关钩子，而是deactivated

• 切回的时候不再执行create和mount相关钩子，而是activated

所以keep-alive是对组件实例的缓存，无需重新渲染

在线验证：入口