Question

最好举一个例子,说明我描述的情况。

类别清单中的四级元件从中页开始,但随着用户的滚动缩小,它仍然处于顶点?

http://www.khanacademy.org/

I know how to make a fixed element. My question is how do i make the element appear by default in the center of the page, but as the user scrolls down, the element will stay at the top.

Answer 1

这里的快速jsFiddle example。基本上,你有一小iv,最初是相对的,然后随着页的推移,职位改为固定职位。 j 彩票与美元(窗口)相重。滚动活动。

j 质量:

var stickerTop = parseInt($( #sticker ).offset().top);
$(window).scroll(function() {
    $("#sticker").css((parseInt($(window).scrollTop()) + parseInt($("#sticker").css( margin-top )) > stickerTop) ? {
        position:  fixed ,
        top:  0px 
    } : {
        position:  relative 
    });
});

CSS:

body {
    width: 960px;
}
#mainbar {
    width: 660px;
    float: left;
}
#sidebar {
    width: 270px;
    float: right;
}
#sticker {
    width: 200px;
    padding: 10px;
    margin-top:25px;
    background: #eee;
    border: 1px solid #ccc;
}

友情链接