<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script src="https://cdn.bootcss.com/vue/2.4.2/vue.min.js"></script>
</head>
<body>
<div id="app">
<input type="text" v-model="items.text" ref="count"/>
<div v-html="number"></div>
</div>
<script>
new Vue({
el: ‘#app‘,
data: {
number: ‘100‘,
items: {
text:‘‘,
},
},
watch:{ //watch()监听某个值（双向绑定）的变化，从而达到change事件监听的效果
items:{
handler:function(){
var _this = this;
var _sum = 100; //字体限制为100个
_this.$refs.count.setAttribute("maxlength",_sum);
_this.number= _sum- _this.$refs.count.value.length;
},
deep:true
}
}
})
</script>
</body>
</html>
原文出处链接地址：http://www.cnblogs.com/xueweijie/p/6859965.html
原文：http://www.cnblogs.com/xushengguan/p/7462767.html