随机图片滚动 

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<script type="text/javascript" src="float.js">
</script>
<script type="text/javascript">
window.onload = function ()
{
    var ali = document.getElementsByTagName('li');
    var flag = 0;
    
    for(var i = 0; i < ali.length; i++)
    {
        fnshow(ali[i]);
    }
    
    function fnshow (li)
    {
        var odiv = li.getElementsByTagName('div')[0];
        function fnshowone ()
        {
            setTimeout(function ()
            {
                flag = flag == 0?-50:0;
                domove(odiv,'top',10,80,flag,fnshowone);
            },Math.round(Math.random()*2000+1000));
        }
        
        fnshowone();
        
    };
};
</script>
<style>
ul{
    margin:50px auto;
    width:220px;
    }
li{
    display:inline-block;
    width:100px;
    height:50px;
    overflow:hidden;
    position:relative;
    list-style-type:none;
    }
div{
    position:absolute;
    left:0px;
    top:0px;
    }    
img{
    width:100px;
    height:50px;
    }    
</style>
</head>

<body>
<ul>
    <li>
        <div>
            <img src="img/5-1.jpg">
            <img src="img/5-2.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-3.jpg">
            <img src="img/5-4.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-5.jpg">
            <img src="img/5-6.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-7.jpg">
            <img src="img/5-8.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-9.jpg">
            <img src="img/5-10.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-11.jpg">
            <img src="img/5-12.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-13.jpg">
            <img src="img/5-14.jpg">
        </div>
    </li>
    <li>
        <div>
            <img src="img/5-15.jpg">
            <img src="img/5-16.jpg">
        </div>
    </li>
</ul>
</body>
</html>
function getstyle(obj,attr)
{
    return obj.currentStyle?obj.currentStyle[attr]:getComputedStyle(obj)[attr];
}


function domove (obj,attr,step,frequency,target,endfn)
{
    step = parseInt(getstyle(obj,attr))<target?step:-step;
    clearInterval(obj.timer);
    obj.timer = setInterval( function ()
    {
        var speed = parseInt(getstyle(obj,attr)) + step;
        if(step>0&&speed>target||step<0&&speed<target)
        {
            speed = target;
        }
        obj.style[attr] = speed + 'px';
        if( speed == target )
        {
            clearInterval(obj.timer);
            endfn&&endfn();
        }
    },frequency); 
};

function opacity(obj,step,target,frequency,endfn)
{
    var currentOpacity = getstyle(obj,'opacity') * 100;
    step = currentOpacity < target?step:-step;
    clearInterval(obj.opacity)
    obj.opacity = setInterval (function ()
    {
        currentOpacity = getstyle(obj,'opacity') *100;
        var nextOpacity = currentOpacity + step;
        if(step>0&& nextOpacity>target || step<0&& nextOpacity < target )
        {
            nextOpacity = target;
        }
    obj.style.opacity = nextOpacity/100;
    obj.style.filter = 'alpha(opacity:)' + nextOpacity +')';
    if(nextOpacity == target )
    {
        clearInterval(obj.opacity);
        endfn&&endfn();
    }    
    },frequency);
    
    
};

function shake(obj,attr,endfn)
{
    if( obj.shaked ) { return;  }
    obj.shaked = true;
    
    var num = 0;
    var timer = null;
    var arr = [];
    var pos = parseInt(getstyle(obj,attr));
    
    for( var i = 20; i > 0; i-=2 )
    {
        arr.push(i,-i);
    }
    arr.push(0);
    
    clearInterval(obj.shake);
    obj.shake = setInterval(function ()
    {
        obj.style[attr] = pos + arr[num] +'px';
        num++;
        if(num==arr.length)
        {
            clearInterval(obj.shake);
            endfn&&endfn();
            obj.shaked = false;
        }
    },50);
};

 

posted @ 2014-12-28 12:05  mayufo  阅读(187)  评论(0)    收藏  举报