jquery 操作滚动条

// 滚动到页面顶部
$('html, body').animate({scrollTop: 0}, 'slow');

// 滚动到页面指定元素位置
var offset = $('#targetElement').offset().top;
$('html, body').animate({scrollTop: offset}, 'slow');

// 设置元素的 scrollTop 值
$('#scrollableDiv').scrollTop(100);

// 获取元素的 scrollTop 值
var scrollTopValue = $('#scrollableDiv').scrollTop();

// 使用 requestAnimationFrame 优化滚动动画
function smoothScrollTo(element, to, duration) {
    var start = element.scrollTop,
        change = to - start,
        currentTime = 0,
        increment = 20;

    var animateScroll = function() {
        currentTime += increment;
        var 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($('#scrollableDiv')[0], 300, 1000);