常见JS效果之图片减速度滚动实现代码
作者：
图片减速度滚动,一般用于产品的展示效果。作为前端，互联网上一些常见效果都要尝试去实现，不能因为公司用不到就不做。
复制代码 代码如下:
<!DOCTYPE html>
<html>
<head>
<meta charset="gb2312" />
<title>图片减速度滚动(by rentj1@163.com;)</title>
<style>
ul{ margin:0; padding:0}
ul{ list-style:none;}
body{font:12px/1.2 "宋体"; }
.scroll_box{ position:relative; height:164px; width:766px; border:1px solid #efefef; overflow:hidden;}
.scroll_box .list{ overflow:hidden; zoom:1; position:absolute;}
.scroll_box .list li{ width:235px; height:164px; padding:0 10px; text-align:center; float:left;}
.scroll_box .list .info{ line-height:1.5}
</style>
</head>
<body>
<div class="scroll_box" id="container">
<ul class="list" id="content">
<li>
<img src="http://img14.360buyimg.com/n4/4587/cd8a8a76-24f4-44d8-876b-12d78cbae588.jpg" />
<div class="info">
兵尼兔 环保大包围专车专用脚垫 米色（专车专用，仅支持在线支付）版型精准 大包围
</div>
<span class="price">会员价：￥288.00</span>
</li>
<li>
<img src="http://img11.360buyimg.com/n4/309/9230eaef-021c-447d-a64b-51ce698822ef.jpg" />
<div class="info">
兵尼兔 环保大包围专车专用脚垫 米色（专车专用，仅支持在线支付）版型精准 大包围
</div>
<span class="price">会员价：￥288.00</span>
</li>
<li>
<img src="http://img10.360buyimg.com/n4/8792/7691b514-a0b3-469e-8a2b-37b219ebc490.jpg" />
<div class="info">
兵尼兔 环保大包围专车专用脚垫 米色（专车专用，仅支持在线支付）版型精准 大包围
</div>
<span class="price">会员价：￥288.00</span>
</li>
<li>
<img src="http://img12.360buyimg.com/n4/285/c675cbb0-3a6f-4703-95fb-e75a7c90b48e.jpg" />
<div class="info">
兵尼兔 环保大包围专车专用脚垫 米色（专车专用，仅支持在线支付）版型精准 大包围
</div>
<span class="price">会员价：￥288.00</span>
</li>
<li>
<img src="http://img12.360buyimg.com/n4/1957/22aa7c6d-4b70-49b8-a985-678b1d0e3781.jpg" />
<div class="info">
兵尼兔 环保大包围专车专用脚垫 米色（专车专用，仅支持在线支付）版型精准 大包围
</div>
<span class="price">会员价：￥288.00</span>
</li>
<li>
<img src="http://img10.360buyimg.com/n4/2314/cf09b35a-eb6d-4a4f-a4dd-3301bfafef99.jpg" />
<div class="info">
兵尼兔 环保大包围专车专用脚垫 米色（专车专用，仅支持在线支付）版型精准 大包围
</div>
<span class="price">会员价：￥288.00</span>
</li>
</ul>
</div>
<script>
untils = {
getComputedStyle: function(elem,syle){
var computedStyle = document.defaultView
&& document.defaultView.getComputedStyle
&& document.defaultView.getComputedStyle(elem,null);
if(!computedStyle){
computedStyle = elem.currentStyle
}
return computedStyle[syle]
},
setStyle: function(elem, name,val){
elem.style[name] = val;
},
get: function(id){
document.getElementById(id)
}
}
function ScrollSlider(container, content){
var clone = content.cloneNode(true);
var initcss= "left:0; top:0";
var contentHeight = content.offsetHeight;
var containerHeight = container.clientHeight;
clone.id = "content-clone";
container.appendChild(clone);
clone.setAttribute("cssText", initcss);
content.setAttribute("cssText", initcss);
clone.style.marginTop = contentHeight+"px";
this.content = content;
this.clone = clone;
this.container = container;
this.containerHeight = containerHeight;
this.contentHeight = contentHeight;
}
ScrollSlider.prototype = {
start: function(delay){
var _this = this;
clearInterval(_this.timer);
_this.timer = setInterval(function(){
_this.scroll();
},delay);
},
scroll: function(){
var marginTop = parseInt(untils.getComputedStyle(this.content, "marginTop"));
var offsetTop = this.contentHeight;
if(isNaN(marginTop))return;
if( -marginTop >= this.contentHeight){
marginTop = this.contentHeight;
}
if(marginTop > 0){
offsetTop = -offsetTop;
}
this.move(marginTop, offsetTop);
},
move: function(marginTop, offsetTop){
var s = this.containerHeight, s1 = 0, _this = this, m = 0;
var timer = setInterval(function(){
var speed = (s-s1)/8;
speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);
s1 += speed;
m = marginTop - s1;
untils.setStyle(_this.content, "marginTop", m + "px");
untils.setStyle(_this.clone, "marginTop", (m + offsetTop)+"px");
if(s-s1 <= 0){
clearInterval(timer);
}
},30);
}
};
var container = document.getElementById("container")
var content = document.getElementById("content")
var xx = new ScrollSlider(container, content);
xx.start(1000*3);
/*
//s=1/2 * at^2
//s (att)/2
//0<s<164
0,-164,-328,164,0
328,164,0,-164,-328,164,0
*/
</script>
</body>
</html>