JavaScript实现仿新浪微博大厅和腾讯微博首页滚动特效源码

<div class="wp">
<ul id="slider" class="slider">
<li><a class="fl" href="javascript:;"><img src="http://t1.qlogo.cn/mbloghead/b9127c4ca63961bace88/50" alt="" /></a>
<p>入山又恐别倾城 世间安得双全 不负如来不负卿</p>
 </li>
<li><a class="fl" href="javascript:;"><img src="http://t1.qlogo.cn/mbloghead/b9127c4ca63961bace88/50" alt="" /></a>
<p>第一最好不相见，如此便可不相恋。</p>
</li>
<li><a class="fl" href="javascript:;"><img src="http://t1.qlogo.cn/mbloghead/b9127c4ca63961bace88/50" alt="" /></a>
<p>那一天 闭目在经殿香雾</p>
 </li>
<li><a class="fl" href="javascript:;"><img src="http://t1.qlogo.cn/mbloghead/b9127c4ca63961bace88/50" alt="" /></a>
<p> 你见 或者不见我 我就在那里 </p>
</li>
</ul>
</div>
<script type="text/javascript">
new slider({id:'slider'})
</script> 

ul, li {margin:0;padding:0;list-style:none}
a{ color:#fff;}
body {margin:0;height:100%;background: #333;}
.wp {position: relative;width:800px;height:400px;overflow:hidden;margin:20px auto;border:4px solid #121212;background:#fff;}
.slider {position: absolute;width: 760px;padding:0 20px;left:0;top: 0;}
.fl {float:left}
.slider img {display:block; padding: 2px; border: 1px solid #ccc} 
.slider li {padding: 20px 0; border-bottom: 1px dashed #ccc;overflow:hidden;width:100%}
.slider p {font-size: 12px;margin:0;padding-left:68px;color:#333;line-height:20px;}

function H$(i) {return document.getElementById(i)}

function H$$(c, p) {return p.getElementsByTagName(c)}
var slider = function () {
function inits (o) {
this.id = o.id;
this.at = o.auto ? o.auto : 3;
this.o = 0;
this.pos();
alert(o);
}
inits.prototype = {
pos : function () {
clearInterval(this.__b);
this.o = 0;
var el = H$(this.id), li = H$$('li', el), l = li.length;
var _t = li[l-1].offsetHeight;
var cl = li[l-1].cloneNode(true);
cl.style.opacity = 0; cl.style.filter = 'alpha(opacity=0)';
el.insertBefore(cl, el.firstChild);
el.style.top = -_t + 'px';
this.anim();
},
anim : function () {
var _this = this;
this.__a = setInterval(function(){_this.animH()}, 20);
},
animH : function () {
var _t = parseInt(H$(this.id).style.top), _this = this;
if (_t >= -1) {
clearInterval(this.__a);
H$(this.id).style.top = 0;
var list = H$$('li',H$(this.id));
H$(this.id).removeChild(list[list.length-1]);
this.__c = setInterval(function(){_this.animO()}, 20);
//this.auto();
}else {
var __t = Math.abs(_t) ?C Math.ceil(Math.abs(_t)*.07);
H$(this.id).style.top = -__t + 'px';
}
},
animO : function () {
this.o += 2;
if (this.o == 100) {
clearInterval(this.__c);
H$$('li',H$(this.id))[0].style.opacity = 1;
H$$('li',H$(this.id))[0].style.filter = 'alpha(opacity=100)';
this.auto();
}else {
H$$('li',H$(this.id))[0].style.opacity = this.o/100;
H$$('li',H$(this.id))[0].style.filter = 'alpha(opacity='+this.o+')';
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},
auto : function () {
var _this = this;
this.__b = setInterval(function(){_this.pos()}, this.at*1000);
}
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return inits;
}();