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Vue的常用钩子函数

vue有8种生命周期函数:

钩子函数触发的行为在此阶段可以做的事情
beforeCreadtedvue实例的挂载元素$el和数据对象data都为undefined,还未初始化。加loading事件
createdvue实例的数据对象data有了,$el还没有结束loading、请求数据为mounted渲染做准备
beforeMountvue实例的$el和data都初始化了,但还是虚拟的dom节点,具体的data.filter还未替换。..
mountedvue实例挂载完成,data.filter成功渲染配合路由钩子使用
beforeUpdatedata更新时触发
updateddata更新时触发数据更新时,做一些处理(此处也可以用watch进行观测)
beforeDestroy组件销毁时触发
destroyed组件销毁时触发,vue实例解除了事件监听以及和dom的绑定(无响应了),但DOM节点依旧存在组件销毁时进行提示

测试代码:

export default { data () { return { todos: [], allCounts: 0, filter: 'all', id: 0, states: ['all', 'active', 'completed'] } }, beforeCreate () { console.log('==============' + 'beforeCreated' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, created () { console.log('==============' + 'created' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, beforeMount () { console.log('==============' + 'beforeMount' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, mounted () { console.log('==============' + 'mounted' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, beforeUpdate () { console.log('==============' + 'beforeUpdate' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, updated () { console.log('==============' + 'updated' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, beforeDestroy () { console.log('==============' + 'beforeDestroy' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) }, destroyed () { console.log('==============' + 'destroyed' + '===================') console.log(this.$el) console.log(this.$data) console.log(this.filter) } }

效果:
刷新vue项目时
改变data中的filter时

本文原创,作者:西决,其版权均为品创网络所有。如需转载,请注明出处:https://www.sxpcwlkj.com/vue/

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