vue实现某元素吸顶或固定位置显示（监听滚动事

mounted () {
 window.addEventListener('scroll', this.handleScroll)
},

handleScroll () {
 var scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop
 console.log(scrollTop)
},

handleScroll () {
 var scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop
 var offsetTop = document.querySelector('#searchBar').offsetTop
 if (scrollTop > offsetTop) {
 this.searchBarFixed = true
 } else {
 this.searchBarFixed = false
 }
},

.searchBar{
 .isFixed{
 position:fixed;
 background-color:#Fff;
 :0;
 z-index:999;
 }
 ul {
 WIDTH:100%;
 height: 40px;
 line-height: 40px;
 display: flex;
 li {
 font-size: 0.8rem;
 text-align: center;
 flex: 1;
 i {
 font-size: 0.9rem;
 padding-left: 5px;
 color: #c;
 }
 }
 border-bottom: 1px solid #ddd;
 }
}

<div class="searchBar" id="searchBar">
 <ul :class="searchBarFixed == true ? 'isFixed' :''">
 <li>区域<i class="iconfont icon-jiantouxia"></i></li>
 <li>价格<i class="iconfont icon-jiantouxia"></i></li>
 <li>房型<i class="iconfont icon-jiantouxia"></i></li>
 <li>更多<i class="iconfont icon-jiantouxia"></i></li>
 </ul>
</div>

destroyed () {
 window.removeEventListener('scroll', this.handleScroll)
},