vue实例从创建到销毁的过程,称为生命周期,共有八个阶段
文档
https://cn.vuejs.org/v2/guide/instance.html#%E7%94%9F%E5%91%BD%E5%91%A8%E6%9C%9F%E5%9B%BE%E7%A4%BA

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>发送AJAX请求</title>
<script src="js/vue.js"></script>
<script src="js/axios.min.js"></script>
<script src="js/vue-resource.min.js"></script>
<script>
window.onload = function() {
let vm = new Vue({
el: '.itany',
data: {
msg: 'welcome to itany'
},
methods: {
update() {
this.msg = '欢迎来到南京网博!';
},
destroy() {
vm.$destroy();
}
},
beforeCreate() {
alert('组件实例刚刚创建,还未进行数据观测和事件配置');
},
created() {
alert('实例已经创建完成,并且已经进行数据观测和事件配置');
},
beforeMount() {
alert('模板编译之前,还没挂载');
},
mounted() {
alert('模板编译之后,已经挂载,此时才会渲染页面,才能看到页面上数据的展示');
},
beforeUpdate() {
alert('组件更新之前');
},
updated() {
alert('组件更新之后');
},
beforeDestroy() {
alert('组件销魂之前');
},
destroyed() {
alert('组件销魂之后');
},
});
}
</script>
</head>
<body>
<div class="itany">
{{msg}}
<br>
<button @click='update'>更新数据</button>
<button @click='destroy'>销魂组件</button>
</div>
</body>
</html>