html部分

<div class="notice_index">
    <b>公告</b>
    <div class="notice_box">
        <ul class="marquee_list" :class="{marquee_top:animate}">
            <li v-for="(item, index) in marqueeList">
                最新消息：
                <span style="color: #999;">{{item.Title}}</span>
                <i style="color: #999;">[ {{item.UpdateTime | moment("YYYY-MM-DD")}} ]</i>
            </li>
        </ul>
    </div>
    <div class="option">
       <button @click="up" >▲</button>
       <button @click="down" >▼</button>
    </div>
</div>

vue部分

created() {
        setInterval(this.showMarquee, 5000)//每5秒調(diào)用
}
methods: {
    showMarquee() {
        this.animate = true;
        setTimeout (() => {
            this.marqueeList.push (this.marqueeList[0]);
            this.marqueeList.shift ();
            this.animate = false;
         }, 1000);
     },
}

我想知道怎么寫up和down