使用定位实现无缝滚动

let ul = document.querySelector(‘ul‘);
let liArr = ul.querySelectorAll(‘li‘);
let olArr = document.querySelector(‘ol‘).querySelectorAll(‘li‘);
let index = 0;
let num = 0;
let timer = setInterval(function () {
            if (index === 0) {
                liArr[0].style.position = ‘static‘;
                ul.style.top = 0;
                num = 0;
            }
            if (index === liArr.length - 1) {
                index = 0;
                liArr[0].style.position = ‘relative‘;
                liArr[0].style.top = liArr.length * 337.5 + ‘px‘;
            } else {
                index++;
            }
            num++;
            olArr.forEach(item => item.classList.remove(‘active‘));
            olArr[index].classList.add(‘active‘);
            startMove(ul, {top: -num*337.5});
}, 2000);