<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Vue.set全局操作</title>
<meta name="flexible" content="initial-dpr=2,maximum-dpr=3" />
<meta name="apple-mobile-web-app-capable" content="yes">
<meta content="yes" name="apple-touch-fullscreen">
<meta content="telephone=no,email=no" name="format-detection">
<meta content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no" name="viewport">
<script src="../assets/js/flexible_css.js"></script>
<script src="../assets/js/flexible.js"></script>
<script src="../assets/js/vue.js"></script>
</head>
<body>
<div id="app">
<p>今日温度：{{temperature}}°C</p>
<p>穿衣建议:{{suggestion}}</p>
<p>
<button @click="add">添加温度</button>
<button @click="reduce">减少温度</button>
</p>
</div>
</body>
<script type="text/javascript">
var suggestion=['T恤短袖','夹克长裙','棉衣羽绒服'];
var app=new Vue({
el:'#app',
data:{
temperature:14,
suggestion:'夹克长裙'
},
methods:{
add:function(){
this.temperature+=5;
},
reduce:function(){
this.temperature-=5;
}
},
// watch:{ // 看守，监视 ／/第一种在构造器里面
// temperature:function(newVal){
// if(newVal>=26){
// this.suggestion=suggestion[0];
// }else if(newVal<26 && newVal >=0)
// {
// this.suggestion=suggestion[1];
// }else{
// this.suggestion=suggestion[2];
// }
// }
// }
})
app.$watch('temperature',function(newVal,oldVal){ ///第二种在构造器外面 实例属性写watch监控
if(newVal>=26){
this.suggestion=suggestion[0];
}else if(newVal<26 && newVal >=0)
{
this.suggestion=suggestion[1];
}else{
this.suggestion=suggestion[2];
}
// 监控属性有两种写法 第一种在构造器里面，第二种在构造器外面
})
</script>
</html>
