1. 侧边栏广告
1 window.onload = window.onresize = window.onscroll = function() {
2 var oDiv = document.getElementById("div1");
3
4 //页面滚动的距离
5 var scrollTop =
6 document.documentElement.scrollTop || document.body.scrollTop;
7
8 //DIV顶部距离可见窗口顶部的距离
9 var t = (document.documentElement.clientHeight - oDiv.offsetHeight) / 2;
10
11 //设置广告的位置
12 oDiv.style.top = scrollTop + t + "px";
13 }
2. 回到顶部
1 window.onload = function() {
2 var oBtn = document.getElementById("btn1");
3 var timer = null;
4 var isSys = false;
5
6 //如果是用户拖动了滚动条,则停止滑动
7 window.onscroll = function() {
8 if (!isSys) {
9 clearInterval(timer);
10 }
11 isSys = false;
12 };
13
14 oBtn.onclick = function() {
15 timer = setInterval(function() {
16 isSys = true;
17
18 //页面滚动的距离
19 var scrollTop =
20 document.documentElement.scrollTop || document.body.scrollTop;
21 var iSpeed = Math.floor(-scrollTop / 8);
22
23 //如果到达顶部,则清除定时器
24 if (scrollTop === 0) {
25 clearInterval(timer);
26 }
27
28 document.documentElement.scrollTop =
29 document.body.scrollTop = scrollTop + iSpeed;
30 }, 30);
31 };
32 };