goToTop() {
let top = document.documentElement.scrollTop; //获取点击时页面的滚动条纵坐标位置
const timeTop = setInterval(() => {
document.documentElement.scrollTop = top -= 50; //一次减50往上滑动
if (top <= 0) {
clearInterval(timeTop);
}
}, 5); //定时调用函数使其更顺滑
},