.offset().top的位移高度是相对于body还是.leftmenu_main li？？？

Question

$(".leftmenu_main li").hover(function () {

    $(this).addClass('hover');

    var menuTop = $(this).offset().top;

    

    var itemsList = $(this).children(".sec_cd");

    var itemsCount = itemsList.find('.sec_icon').length;

    itemsList.css("top", subMenuTop).fadeIn("fast");

}, function () {

    $(".sec_cd").hide();

    $(this).removeClass('hover');

});

Answer 1

为什么不查 API。Get the current coordinates of the first element in the set of matched elements, relative to the document.