Vue.js中的生命周期钩子函数
2019-01-16 本文已影响0人
雪域狼王jayh
这儿主要是为了介绍一下Vue.js的生命周期，读者可以类比成spring 甚至 java的生命周期
生命周期图解
生命周期.png
生命周期探究
下面是一段代码，对理解生命周期或许有点帮助
<!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>
生命周期探究
| 生命周期钩子 | 对应的处理过程 | 使用方法 |
|---|---|---|
| beforecreated | el 和 data 并未初始化 | eg: 可以在这加个loading事件 |
| created | 完成了 data 数据的初始化，el没有 | 在这发起后端请求，拿回数据，配合路由钩子做一些事情 |
| beforeMount | 完成了 el 和 data 初始化 | 在某组件删除之前的再次确认 |
| mounted | 完成挂载 | 当前组件已被删除，清空相关内容 |
