vue touch事件，长按1秒显示删除按钮。我是这样写的，但是实现不了，请问应该怎么修改呢？

<div class="card" v-for="(floor,index) in floors_list" @touchstart="showDeleteButton" @touchend="clearLoop">
    <div class="delete-button" :class="{'delete-button-show': isDeleting}" @click="clickDelFloor(index)">x</div>
</div>

showDeleteButton() {
    clearInterval(this.Loop);//再次清空定时器，防止重复注册定时器
    this.Loop=setTimeout(function(){
        this.isDeleting = true;
    },1000);
},
clearLoop() {
    clearInterval(this.Loop);
},