JS瀑布流布局模式(1)

在实际的项目中，偶尔会用到一种布局——瀑布流布局。瀑布流布局的特点是，在多列布局时，可以保证内容区块在水平方向上不产生大的空隙，类似瀑布的效果。简单的说，在垂直列表里，内容区块是一个挨着一个的。当内容较多且不固定时，就依赖于html结构的顺序，非常受限制。这里给了一个简单的例子，只要传入列表的数量和宽度，就可以动态的将数据放到对应的列里。

 

原理

1.定义两个容器，一个是存放内容，一个是要展示的列表。

2.将每列的offsetHeight存入一个数组里，比较得出最小的那一列，然后把数据放到最小的列里。判断当存放内容的容器为空时，就说明里面的数据已经全部放到对应的列里了。

注意：这个函数需要在window.onload之后执行，不然每个内容区块的高度读不出来，会导致每一列的offsetHeight不准确。

 

源代码：

DOCTYPE html>
<</span>html>
<</span>head>
<</span>meta http-equiv="Content-Type" Content="text/html; charset=utf-8;">
<</span>title>waterfall布局</</span>title>
<</span>meta name="author" content="rainna" />
<</span>meta name="keywords" content="rainna's js lib" />
<</span>meta name="description" content="waterfall布局" />
<</span>style>
*{margin:0;padding:0;}
li{list-style:none;}

.list li{float:left;min-height:10px;margin:0 0 0 20px;}
.list .item{margin:0 0 10px;}
.list img{display:block;width:100%;}
</</span>style>
</</span>head>

<</span>body>
<</span>div class="content" id="content">
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_101.jpg" />01</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_102.jpg" />02</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_103.jpg" />03</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_104.jpg" />04</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_105.jpg" />05</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_106.jpg" />06</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_107.jpg" />07</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_108.jpg" />08</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_109.jpg" />09</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_110.jpg" />10</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_111.jpg" />11</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_112.jpg" />12</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_113.jpg" />13</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_114.jpg" />14</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_115.jpg" />15</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_116.jpg" />16</</span>div>
    <</span>div class="item"><</span>img src="http://cued.xunlei.com/demos/publ/img/P_117.jpg" />17</</span>div>
</</span>div>
<</span>div class="list" id="list"></</span>div>

<</span>script>
var waterFall = {
    content:document.getElementByIdx_x_x('content'),    //存放内容的容器
    list:document.getElementByIdx_x_x('list'),   //将要展示的列表容器

    setOptions:function(options){
        options = options || {};
        this.colNum = options.num || 3;   //显示的列数，默认显示3列 
        this.colWidth = options.width || 200;   //每列的宽度
    },
    
    //构建列数
    setColumn:function(){
        var self = this;
        var html = '';
        for(var i=0,l=self.colNum;i<</span>l;i++){
            html += '
'+ self.colWidth +'px;">
'; } self.list.innerHTML = html; self.column = self.list.getElementsByTagName_r('li'); }, //计算最小高度的列 setMinHeightCol:function(){ var self = this; var heiArray = []; var minIndex = 0,index = 1; for(var i=0,l=self.colNum;i<</span>l;i++){ heiArray[i] = self.column[i].offsetHeight; } while(heiArray[index]){ if(heiArray[index] <</span> heiArray[minIndex]){ minIndex = index; } index ++; } return self.column[minIndex]; }, //填充内容 setCont:function(cnt){ var self = this; self.setMinHeightCol().a(cnt); if(!!self.content.children[0]){ self.setCont(self.content.children[0]); } }, init:function(options){ var self = this; window.onload = function(){ self.setOptions(options); self.setColumn(); self.setCont(self.content.children[0]); } } }; waterFall.init();//使用初始化参数 waterFall.init({num:4,width:100}); </</span>script> </</span>body> </</span>html>