Vue入門（三）Vue生命週期

努力--坚持發表於2024-09-01
Vue

一、Vue生命週期
Vue生命週期的八個階段

建立前 beforeCreate
建立後 created
載入前 beforeMount
載入後 mounted
更新前 beforeUpdate
更新後 updated
銷燬前 beforeDestroy
銷燬後 destroyed

Vue生命週期的八個階段如下圖：

二、生命週期示例
生命週期示例程式碼：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>生命週期</title>
    <script src="vue/vue.js"></script>
</head>
<body>
    <div id="app">
        {{message}}
    </div>
</body>
<script>
    let vm = new Vue({
                el: '#app',
                data: {
                    message: 'Vue的生命週期'
                },
                beforeCreate: function() {
                    console.group('------beforeCreate建立前狀態------');
                    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
                },
                created: function() {
                    console.group('------created建立完畢狀態------');
                    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掛載前狀態------');
                    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.$data); //已被初始化  
                    console.log("%c%s", "color:red", "message: " + this.message); //已被初始化  
                },
                mounted: function() {
                    console.group('------mounted 掛載結束狀態------');
                    console.log("%c%s", "color:red", "el     : " + this.$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 更新前狀態===============》');
                    let dom = document.getElementById("app").innerHTML;
                    console.log(dom);
                    console.log("%c%s", "color:red", "el     : " + this.$el);
                    console.log(this.$el);
                    console.log("%c%s", "color:red", "data   : " + this.$data);
                    console.log("%c%s", "color:red", "message: " + this.message);
                },
                updated: function() {
                    console.group('updated 更新完成狀態===============》');
                    let dom = document.getElementById("app").innerHTML;
                    console.log(dom);
                    console.log("%c%s", "color:red", "el     : " + this.$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 銷燬前狀態===============》');
                    console.log("%c%s", "color:red", "el     : " + this.$el);
                    console.log(this.$el);
                    console.log("%c%s", "color:red", "data   : " + this.$data);
                    console.log("%c%s", "color:red", "message: " + this.message);
                },
                destroyed: function() {
                    console.group('destroyed 銷燬完成狀態===============》');
                    console.log("%c%s", "color:red", "el     : " + this.$el);
                    console.log(this.$el);
                    console.log("%c%s", "color:red", "data   : " + this.$data);
                    console.log("%c%s", "color:red", "message: " + this.message);
                }
            });
 
            //vm.$destroy(); 方法
            
</script>
</html>

執行結果如下圖：

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