javascript实现瀑布流效果（固定宽度）

<div id="content">
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/01.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/02.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="">
            <a href="###"><img src="images/03.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/04.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/05.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/06.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/07.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/08.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/09.jpg" alt="" /></a>
        </div>
    </div>
    <div class="box">
        <div class="imgBox">
            <a href="###"><img src="images/10.jpg" alt="" /></a>
        </div>
    </div>
</div>

*{ margin:0; padding:0;}
body{ background-color:#f2f2f2;}
#content{ padding: 10px 0px; margin:0 auto; position:relative;}
.box{ padding:10px; width:310px; height:auto; float:left;}
.imgBox{ border:solid 1px #dcdcdc; width:310px;}
.imgBox img{ width:310px; height:auto;}

window.onload=function(){    
    setPosition(‘content‘,‘box‘);    
    //通过json字符串模拟加载内容
    var imgArray={‘date‘:[{‘src‘:‘05.jpg‘},{‘src‘:‘06.jpg‘},{‘src‘:‘07.jpg‘},{‘src‘:‘08.jpg‘}]}    
    
    //滚动到页面底部（最后一张图片的顶部）时开始加载json内容
    window.onscroll=function(){
        if(getFlag()){ //判断是否滚动到最后一张
            var oContent=document.getElementById(‘content‘); //获取外部容器    
            for(var i=0;i<imgArray.date.length;i++){        
                var oDiv=document.createElement(‘div‘);
                oDiv.className=‘box‘;
                oContent.appendChild(oDiv);
                var oImgDiv=document.createElement(‘div‘);
                oImgDiv.className=‘imgBox‘;
                oDiv.appendChild(oImgDiv);
                var oImg=document.createElement(‘img‘);
                oImg.src=‘images/‘+imgArray.date[i].src;
                oImgDiv.appendChild(oImg);        
            }
            setPosition(‘content‘,‘box‘);    
        }
    }
}

//元素排列
function setPosition(parents,content){    
    var oContent=document.getElementById(‘content‘); //获取外部容器    
    var aBox=getByClass(oContent,content); //获取classname为box的元素集合
    var oneWidth=aBox[0].offsetWidth;      //获取单个box的宽度
    var docWidth=document.documentElement.clientWidth||document.body.clientWidth; //获取窗口可视区域宽度
    var num=Math.floor(docWidth/oneWidth);   
    oContent.style.width=num*oneWidth+‘px‘;  //设置外部容器的宽度    
    var result=[];
    for(var i=0;i<aBox.length; i++){
        if(i<num){
            result[i]=aBox[i].offsetHeight; //判断是否为第一行，然后把第一行中每个aBox的高度存入定义的result数组中
        }else{
            var minHeight=Math.min.apply(null,result);  //获取result数组中最小的值
            var minIndex=getIndex(result,minHeight);  //获取result数组中最小值的索引
            aBox[i].style.position=‘absolute‘;   
            aBox[i].style.top=minHeight+10+‘px‘;
            aBox[i].style.left=aBox[minIndex].offsetLeft+‘px‘;
            result[minIndex]=result[minIndex]+aBox[i].offsetHeight;
        }        
    }    
}
//获取当前索引值
function getIndex(parents,name){
    for(var i=0;i<parents.length;i++){
        if(parents[i]==name){
            return i;
        }
    }    
}
//通过class选取元素方法
function getByClass(oParent,name){
    var result=[];
    var aArr=oParent.getElementsByTagName(‘*‘);
    for(var i=0; i<aArr.length; i++){
        if(aArr[i].className==name){
            result.push(aArr[i]);
        }
    }
    return result;
}
//判断是否滚动到最后
function getFlag(){
    var oContent=document.getElementById(‘content‘);
    var aBox=getByClass(oContent,‘box‘); 
    var lastTop=aBox[aBox.length-1].offsetTop;
    var clientHeight=document.documentElement.clientHeight||document.body.clientHeight;
    var scorllTop=document.documentElement.scrollTop||document.body.scrollTop;
    if((clientHeight+scorllTop)>lastTop){
        return true;
    }else{
    return false;
    }
}