<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>vue</title>
<link rel="stylesheet" href="">
<!--<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>-->
<!--<script type="text/javascript" src="../js/jquery-2.1.4.min.js"></script>-->
<script type="text/javascript" src="../js/vue.js"></script>
</head>
<body>
<div id="vue">
<div>
<span v-if="num > 0" v-on:click="dec(num)">-</span>
<input v-model="num" type="text">
<span v-on:click="inc(num)">+</span>
</div>
</div>
</body>
<script type="text/javascript">
var app = new Vue({
el: "#vue",
methods:{
dec:function(num){
if(app.num>0){
app.num=num-1;
console.log(app.num);
}
},
inc:function(num){
app.num=num+1;
console.log(app.num);
}
},
data:{
num:0,
}
});
</script>
</html>
效果:
