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Vue2.0生命周期--补习

Vue2.0生命周期--补习

作者: alanwhy | 来源:发表于2019-04-14 22:30 被阅读11次
    说明

    因为自己对Vue生命周期老忘,对有些钩子不是很常用,所以特意再温习一遍,顺便更新文章~借鉴了一位兄台的总结。

    一张图

    vue生命周期.png

    一段代码

    <!DOCTYPE html>
    <html>
    <head>
        <title></title>
        <script type="text/javascript" src="https://cdn.jsdelivr.net/vue/2.1.3/vue.js"></script>
    </head>
    <body>
    
    <div id="app">
         <p>{{ message }}</p>
    </div>
    
    <script type="text/javascript">
        
      var app = new Vue({
          el: '#app',
          data: {
              message : "xuxiao is boy" 
          },
           beforeCreate: function () {
                    console.group('beforeCreate 创建前状态===============》');
                   console.log("%c%s", "color:red" , "el     : " + this.$el); //undefined
                   console.log("%c%s", "color:red","data   : " + this.$data); //undefined 
                   console.log("%c%s", "color:red","message: " + this.message)  
            },
            created: function () {
                console.group('created 创建完毕状态===============》');
                console.log("%c%s", "color:red","el     : " + this.$el); //undefined
                   console.log("%c%s", "color:red","data   : " + this.$data); //已被初始化 
                   console.log("%c%s", "color:red","message: " + this.message); //已被初始化
            },
            beforeMount: function () {
                console.group('beforeMount 挂载前状态===============》');
                console.log("%c%s", "color:red","el     : " + (this.$el)); //已被初始化
                console.log(this.$el);
                   console.log("%c%s", "color:red","data   : " + this.$data); //已被初始化  
                   console.log("%c%s", "color:red","message: " + this.message); //已被初始化  
            },
            mounted: function () {
                console.group('mounted 挂载结束状态===============》');
                console.log("%c%s", "color:red","el     : " + this.$el); //已被初始化
                console.log(this.$el);    
                   console.log("%c%s", "color:red","data   : " + this.$data); //已被初始化
                   console.log("%c%s", "color:red","message: " + this.message); //已被初始化 
            },
            beforeUpdate: function () {
                console.group('beforeUpdate 更新前状态===============》');
                console.log("%c%s", "color:red","el     : " + this.$el);
                console.log(this.$el);   
                   console.log("%c%s", "color:red","data   : " + this.$data); 
                   console.log("%c%s", "color:red","message: " + this.message); 
            },
            updated: function () {
                console.group('updated 更新完成状态===============》');
                console.log("%c%s", "color:red","el     : " + this.$el);
                console.log(this.$el); 
                   console.log("%c%s", "color:red","data   : " + this.$data); 
                   console.log("%c%s", "color:red","message: " + this.message); 
            },
            beforeDestroy: function () {
                console.group('beforeDestroy 销毁前状态===============》');
                console.log("%c%s", "color:red","el     : " + this.$el);
                console.log(this.$el);    
                   console.log("%c%s", "color:red","data   : " + this.$data); 
                   console.log("%c%s", "color:red","message: " + this.message); 
            },
            destroyed: function () {
                console.group('destroyed 销毁完成状态===============》');
                console.log("%c%s", "color:red","el     : " + this.$el);
                console.log(this.$el);  
                   console.log("%c%s", "color:red","data   : " + this.$data); 
                   console.log("%c%s", "color:red","message: " + this.message)
            }
        })
    </script>
    </body>
    </html>
    

    一些说明

    • beforecreated:el 和 data 并未初始化
    • created:完成了 data 数据的初始化,el没有 ,可以进行和后台数据的请求,之后一起渲染DOM,如果请求的数据跟DOM没啥关系,可以放到mounted中(但是请求是异步,所以体验可能也还好)
    • beforeMount:完成了 el 和 data 初始化,未挂载
    • mounted :完成挂载
    • beforeDestroy:整个Vue实例都在,可以进行正常的操作,但是函数执行完,就将全部销毁
    • destroyed:vue实例销毁,什么都干不了了

    原文链接:Vue2.0 探索之路——生命周期和钩子函数的一些理解

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