js 元素scrolltop

// 获取元素的 scrollTop 值
let scrollTopValue = document.getElementById('myElement').scrollTop;

// 设置元素的 scrollTop 值
document.getElementById('myElement').scrollTop = 100;

function smoothScrollTo(element, to, duration) {
    let start = element.scrollTop;
    let change = to - start;
    let currentTime = 0;
    let increment = 20;

    function animateScroll() {
        currentTime += increment;
        let val = Math.easeInOutQuad(currentTime, start, change, duration);
        element.scrollTop = val;
        if (currentTime < duration) {
            requestAnimationFrame(animateScroll);
        }
    }

    animateScroll();
}

// 缓动函数
Math.easeInOutQuad = function (t, b, c, d) {
    t /= d / 2;
    if (t < 1) return c / 2 * t * t + b;
    t--;
    return -c / 2 * (t * (t - 2) - 1) + b;
};

// 使用示例
smoothScrollTo(document.getElementById('myElement'), 500, 1000);