// 组件挂载后添加监听事件 mounted () {window.addEventListener('scroll', this.handleScroll) }, methods: {// 我这里监听的是侧边的滚动条handleScroll: () => {// 滚动时,距离顶部的距离var scrollTop = document.documentElement.scrollTop || document.body.scrollTopvar viewHeight = window.screen.height// 当滚动距离大于屏幕十分之一document.getElementById('rollbar').style.display = scrollTop > viewHeight / 10 ? 'block' : 'none'} }