获取元素(这里定位元素A)距离顶部的高度,接着设定scroll滚动的事件,比如超过那个高度,把A的位置设定为fixed,小于该高度,修改回relative. 方法一: $(function() { var elm = $('.nav'); var startPos = $(elm).offset().top; $.event.add(window, "scroll", function() { var p = $(window).scrollTop(); $(elm).css('pos…
用JS操作,body元素的scrollTop var getTop = document.getElementById("get-top"); var head = document.getElementById("head"); getTop.onclick = function () { var time = setInterval(function () { document.body.scrollTop = document.body.scrollTop -…