87,909
社区成员
发帖
与我相关
我的任务
分享
<style>
*{padding:0;margin:0;}
#cc{width:200px;height:200px;background:#ccc;}
.fixed{position:fixed;top:0;}
</style>
<div style="height:140px"></div>
<div style="height:40px"></div>
<div style="height:200px"></div>
<div id="parent">
<div id="cc"></div>
</div>
<div style="height:5000px"></div>
<script>
window.onscroll = function() {
var cc = document.getElementById("cc");
var top = document.documentElement.scrollTop || document.body.scrollTop;
var stop = document.getElementById("parent").offsetTop;
if (top >= stop) {
cc.className = "fixed";
} else {
cc.className = "";
}
}
</script>
var stop;
window.onload = function() {
var cc = document.getElementById("cc");
stop = cc.offsetTop;
window.onscroll = winscroll;
winscroll();
}
function winscroll() {
var cc = document.getElementById("cc");
var top = document.documentElement.scrollTop || document.body.scrollTop;
if (top >= stop) {
cc.className = "fixed";
} else {
cc.className = "";
}
}