v-model 指令，用于在表单类元素上双向绑定数据
用＠input 来替代 v-model 示例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
姓名:<textarea type="text" @input="handle" cols=20 rows=3></textarea><br/>
<span>输入的姓名是:{{name}}</span>
</div>
<script>
var v=new Vue({
el:"#app",
data:{
name:""
},
methods:{
handle:function(e){
this.name=e.target.value;
}
}
});
</script>
</body>
</html>