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  • vue---生命周期函数

    vue中所有的钩子函数:

    • beforeCreate(创建前)
    • created(创建后)
    • beforeMount(载入前)
    • mounted(载入后)
    • beforeUpdate(更新前)
    • updated(更新后)
    • beforeDestroy(销毁前)
    • destroyed(销毁后)

    生命周期函数

    <!DOCTYPE html>
    <html lang="en">
    
        <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            <meta http-equiv="X-UA-Compatible" content="ie=edge">
            <title>vue生命周期学习</title>
            <script src="https://cdn.bootcss.com/vue/2.4.2/vue.js"></script>
        </head>
    
        <body>
            <div id="app">
                <input v-model="message"></input>
                <h1>{{message1}}</h1>
            </div>
        </body>
        <script>
            var vm = new Vue({/*创建vue对象*/
                el: '#app',/****挂载目标****/
                data: {/****数据对象****/
                    message: 'Hello World!'
                },
                computed:{/****实现某一属性的实时计算****/
                    message1:function(){
                        return this.message.split("").reverse().join("");
                    }
                },
                watched:{/****检测某一属性值的变化****/
    
                },
                methods:{/****组件内部的方法****/
    
                },
    
                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)//undefined
                },
                /**
                 * 1.在beforeCreate和created钩子之间,程序开始监控Data对象数据的变化及vue内部的初始化事件
                 * 
                 * */
                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
                },
                /**
                 * 2.在created和beforeMount之间,判断是否有el选项,若有则继续编译,无,则暂停生命周期;
                 * 然后程序会判断是否有templete参数选项,若有,则将其作为模板编译成render函数。若无,则将外部html作为模板编译(template优先级比外部html高)
                 * 
                 * */
                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.$data); //已被初始化  
                    console.log("%c%s", "color:red", "message: " + this.message); //已被初始化  
                },
                /**
                 * 3.在beforeMount和mounted之间,程序将上一步编辑好的html内容替换el属性指向的dom对象或者选择权对应的html标签里面的内容
                 * 
                 * */
                mounted: function() {
                    console.group('------mounted 挂载结束状态------');
                    console.log("%c%s", "color:red", "el     : " + this.$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 
                },
                /**
                 * 4.mounted和beforeUpdate之间,程序实时监控数据变化
                 * 
                 * */
                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.$data);
                    console.log("%c%s", "color:red", "message: " + this.message);
                },
                /**
                 * 5.beforeUpdate和updated之间,实时更新dom
                 * 
                 * */
                updated: function() {
                    console.group('updated 更新完成状态===============》');
                    console.log("%c%s", "color:red", "el     : " + this.$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.$data);
                    console.log("%c%s", "color:red", "message: " + this.message);
                },
                /**
                 * 6.实例销毁
                 * 
                 * */
                destroyed: function() {
                    console.group('destroyed 销毁完成状态===============》');
                    console.log("%c%s", "color:red", "el     : " + this.$el);
                    console.log(this.$el);
                    console.log("%c%s", "color:red", "data   : " + this.$data);
                    console.log("%c%s", "color:red", "message: " + this.message)
                }
            })
        </script>
    
    </html>
    

      

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  • 原文地址:https://www.cnblogs.com/alone2015/p/9211906.html
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