js控制滚动条滚动的两种简单方法

var element = document.getElementById('myElement'); // 获取需要滚动的元素
element.scrollTop = 100; // 滚动到距离顶部100像素的位置

var element = document.getElementById('myElement'); // 获取需要滚动的元素
var targetPosition = 100; // 滚动到距离顶部100像素的位置
var duration = 500; // 滚动动画的持续时间（毫秒）
var startTime = null; // 动画开始时间
 
function scrollTo(timestamp) {
  if (!startTime) startTime = timestamp;
  var progress = timestamp - startTime;
  var position = Math.min(progress / duration * targetPosition, targetPosition);
  element.scrollTop = position;
  if (progress < duration) {
    window.requestAnimationFrame(scrollTo);
  }
}
 
window.requestAnimationFrame(scrollTo); // 开始滚动动画

window.addEventListener('scroll', () => {
    scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop;
  })

const ScrollTop = (number = 0, time) => {
  if (!time) {
    document.body.scrollTop = document.documentElement.scrollTop = number;
    return number;
  }
  const spacingTime = 20; // 设置循环的间隔时间  值越小消耗性能越高
  let spacingInex = time / spacingTime; // 计算循环的次数
  let nowTop = document.body.scrollTop + document.documentElement.scrollTop; // 获取当前滚动条位置
  let everTop = (number - nowTop) / spacingInex; // 计算每次滑动的距离
  let scrollTimer = setInterval(() => {
    if (spacingInex > 0) {
      spacingInex--;
      ScrollTop(nowTop += everTop);
    } else {
      clearInterval(scrollTimer); // 清除计时器
    }
  }, spacingTime);
}

ScrollTop(scrollTop, 500)