一、加载渲染过程
父beforeCreate->父created->父beforeMount->子beforeCreate->子created->子beforeMount->子mounted->父mounted二、子组件更新过程
父beforeUpdate->子beforeUpdate->子updated->父updated三、父组件更新过程
父beforeUpdate->父updated四、销毁过程
父beforeDestroy->子beforeDestroy->子destroyed->父destroyed