原生JavaScript+LESS实现瀑布流

HTML(注意包裹关系,方便js调用)


 <body>

     <div id="main">

         <div class="box">

             <div class="pic">

                 <img src="images/0.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/1.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/2.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/3.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/4.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/2.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/3.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/4.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/5.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/6.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/7.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/3.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/4.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/5.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/3.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/4.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/5.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/6.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/7.jpg" alt="">

             </div>

         </div>

         <div class="box">

             <div class="pic">

                 <img src="images/3.jpg" alt="">

             </div>

         </div>

     </div>

 </body>

LESS(less预编译)


 * {

     margin: 0;

     padding: 0;

 }

 #main {

     position: relative;

 

 }

 .box {

     padding:15px 0 0 15px;

     float:left;

 }

 .pic {

     padding: 10px;

     border: 1px solid #ccc;

     border-radius: 5px;

     box-shadow: 0px 0px 5px #ccc;

     img {

         width:165px;

         height:auto;

     }

 }

JavaScript(自己理解的注解)

(函数存在一定瑕疵,仅用于学习理解)


 window.onload = function () {

     waterfall("main","box");

     //调用自定义函数;作用于main下的每一个box元素;

     var dataInt = { "data":[{"src":"7.jpg"},{"src":"8.jpg"},{"src":"9.jpg"},{"src":"6.jpg"}]}

     //模拟json数据;

     window.onscroll = function () {

         if (checkScrollSlide) {

         //调用自定义函数;根据函数返回值确定滚动是否超出范围;

             var oParent = document.getElementById("main");

             for (var i = 0; i < dataInt.data.length; i++) {

                 var oBox = document.createElement("div");

                 oBox.className = "box";

                 oParent.appendChild(oBox);

                 //创建box块

                 var oPic = document.createElement("div");

                 oPic.className = "pic"; 

                 oBox.appendChild(oPic);

                 //创建pic块

                 var oImg = document.createElement("img");

                 //创建img元素

                 oImg.src = "images/"+dataInt.data[i].src;

                 //设置图片引用;

                 oPic.appendChild(oImg);

             };

             waterfall("main","box");

             //将动态生成的数据块进行流式布局;

         };

     };

 };

 //流式布局主函数,自动调整数据块的位置;

 function waterfall (parent,box) {

     //将main下的所有box元素取出;"parent"代表父级,box代表box元素;

     var oParent = document.getElementById(parent);

     //将父级元素赋值给变量oParent;

     var oBoxs = getByClass(oParent,box);

     //通过自定义函数,获取父级下的每一个box元素;得到的是所有box元素的集合;

     //再次将这个得到的box元素的集合赋值给oBoxs;(因为作用域问题,变量不共用);

     // console.log(oBoxs.length);

     //在控制台中打印出box元素的数量,用于调试;

     var oBoxW = oBoxs[0].offsetWidth;

     //计算出每一列的宽度;offsetWidth包含内边距在内的宽度;

     // console.log(oBoxW);测试;

     var cols = Math.floor(document.documentElement.clientWidth/oBoxW);

     //计算整个页面显示的列数(页面宽/box的宽);

     oParent.style.cssText = "width:"+oBoxW*cols+"px;margin:0 auto";

     //父元素main的宽度=每一列的宽*列数;并且左右居中;

     var hArr = [];

     //存放每一列高度的数组;

     for (var i = 0; i < oBoxs.length; i++) {

     //遍历oBoxs数组;

         if (i<cols) {

         //这里符合条件的是第一行的每列的第一个;

             hArr.push(oBoxs[i].offsetHeight);

             //得出每一列的高度放入数组中;

         }else{

         //这里的box元素已经不是第一行的元素了;

             var minH = Math.min.apply(null,hArr);

             //得出第一行的最小高度并赋值给变量;

             // console.log(minH);

             var index = getMinhIndex(hArr,minH);

             //调用自定义函数获取这个变量的index值;

             oBoxs[i].style.position = "absolute";

             oBoxs[i].style.top = minH+"px";

             oBoxs[i].style.left = oBoxW*index+"px";

             //设置当前元素的位置;

             //当前元素的left值=顶上的元素的index值*每列的宽度;

             //oBoxs[i].style.left = oBoxs[index].offsetLeft+"px";

             //第二种获取当前元素的left值;

             //此时在第index列添加了一个box元素;

             hArr[index]+=oBoxs[i].offsetHeight;

             //每一列更新后的高度=每一列原来的高度+后来添加的box元素的高度;

         };

     };

 };

 //js原生通过Class获取元素;

 function getByClass (parent,claName) {

     //通过class获取元素;(在父级parent的容器下获取claName的元素;)

     var boxArr = new Array();

     //声明数组,用来存储获取到的所有class为box的元素;

     var oElements = parent.getElementsByTagName("*")

     //声明变量用来存储此父元素下的所有子元素(*);

     for (var i = 0; i < oElements.length; i++) {

     //遍历数组oElements;

         if (oElements[i].className==claName) {

         //如果数组中的某一个元素的calss类与参数claName相同;

             boxArr.push(oElements[i]);

             //则把遍历到的这个box元素归类到boxArr数组;

         };

     };

     return boxArr;

     //调用数组后,经过一系列函数,遍历;将得到的数组返回给调用的函数;

 };

 //获取数组元素的index值;

 function getMinhIndex (arr,val) {

 //arr是父级数组;val是当前元素;

     for(var i in arr){

     //从0开始遍历;

         if(arr[i]==val){

         //找到当前元素在数组中对应的index值;

             return i;

             //函数返回值即是当前元素的index值;

         };

     };

 };

 //检测是否具备了滚动加载数据块的条件;

 function checkScrollSlide () {

     var oParent = document.getElementById("main");

     var oBoxs = getByClass(oParent,"box");

     var lastBoxH = oBoxs[oBoxs.length-1].offsetTop+Math.floor(oBoxs[oBoxs.length-1].offsetHeight/2);

     //最后一个box元素距离页面顶部的高度(找到最后一个box(oBoxs.lenght-1)的offsetTop)+自身的一半;

     var scrollTop = document.body.scrollTop || document.documentElement.scrollTop;

     //浏览器滚动条滚动的距离;

     // console.log(scrollTop);

     var height = document.body.clientHeight || document.documentElement.clientHeight;

     //浏览器视口的高度;

     // console.log(height);

     return (lastBoxH<scrollTop+height)?true:false;

     //页面滚动的距离是否大于最后一个box元素的offsetTop;

 };

总结:

用瀑布流来展现照片再好不过了,下面是瀑布流(每一行的长度等于浏览器窗口的长度)的一种实现方式,也可以用css3实现,很简单,谷歌一下你就知道。
我的思路大概是一张一张的图片插入,当这一行的图片保持长宽比例不变并且高度低于250时就完成一个了循环,即这一行插入进去了,。
然后进入下一个循环插入下一行。