SOURCE

 var app= new Vue({
        el:"#app",
        data:{
            message:"黑马程序员",
        },
        methods:{
            getM:function(){
                alert(this.message);
            },
            setM:function(){
                this.message="123"
            }
        }
 })

<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<div id="app">
    <input type="text" v-model="message" @keyup.enter="getM">
    <input type="button" value="修改message" @click="setM">
    
</div>