javascript实现瀑布流自适应遇到的问题及解决方案

2019-11-20 13:18:02

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这几天看了Amy老师的用javascript实现瀑布流，我跟着把代码敲出来。发现这样写只能第一次载入时适应屏幕，以后改变窗口大小就不能做到自适应了。

于是我想到了用window.onresize来使得瀑布流函数从新加载来达到目的，

window.onload=function(){
    //瀑布流函数
    waterfall('content','box');
    //模拟数据加载
    var dataInt = {"data":[{"src":"01.jpg"},{"src":"02.jpg"},{"src":"03.jpg"},{"src":"04.jpg"},{"src":"05.jpg"},{"src":"06.jpg"},{"src":"07.jpg"}]}
    //当屏幕大小改变时从新执行瀑布流函数 达到从新适应的作用
    window.onresize=function(){
//      waterfall('content','box');
       setTimeout(function() {waterfall('content','box');}, 200);
    }
    window.onscroll=function(){
        if(checkScroll()){
            var oparent = document.getElementById('content');
            //将熏染的数据添加入html中
            for(var i=0;i<dataInt.data.length;i++){
                var obox = document.createElement("div");
                obox.className = "box";
                oparent.appendChild(obox);
                var opic = document.createElement("div");
                opic.className = "pic";
                obox.appendChild(opic);
                var oImg = document.createElement("img");
                oImg.src="img/"+dataInt.data[i].src;
                opic.appendChild(oImg);
            }
                waterfall('content','box');
        }
    }
}

当屏幕缩小时是可以的，但是从缩小的放大就出现了BUG

看没看到后面几列的顶部回不来了，
于是我打开开发工具看是怎么回事，

第3 4 5个div中不应该有style,是因为缩小的时候给他添加上去的，而放大了他没有清除所以保留下来了就会出现这个样子于是：我在瀑布流函数里加了句aBox[i].style.cssText ='';使得每次进来都清空style

复制代码代码如下:

function waterfall(parent,box){
    //将content下所有class box取出来
    var aParent = document.getElementById(parent);
    var aBox = getBclass(aParent,box);
    //获取盒子的宽度
    var aBoxW = aBox[0].offsetWidth;
    //用浏览器的可是宽度除以box宽度 得到列数
    var cols = Math.floor(document.documentElement.clientWidth/aBoxW);
    //设定 content的宽度 和居中
    aParent.style.cssText = 'width:'+aBoxW*cols+'px;height:auto;position: relative; margin:0 auto;padding-right:15px';
    //创建每一列的高度数组
    var hArr=[];
    for(var i=0; i<aBox.length;i++){
        aBox[i].style.cssText ='';
        if(i<cols){
            hArr.push(aBox[i].offsetHeight); 
        }else{
            var minH = Math.min.apply(null,hArr);
            var index = getMinIndex(hArr,minH);  //找出高最矮的 索引值
            //console.log(aBoxW);
            aBox[i].style.position = 'absolute';
            aBox[i].style.top = minH+'px';
            aBox[i].style.left = aBoxW*index+'px';
            hArr[index]+=aBox[i].offsetHeight;
        }
    }
}

这样就解决了缩小后回不来的BUG，可以正常自适应了

最后我把整个的javascript 贴出来

复制代码代码如下:

window.onload=function(){
    //瀑布流函数
    waterfall('content','box');
    //模拟数据加载
    var dataInt = {"data":[{"src":"01.jpg"},{"src":"02.jpg"},{"src":"03.jpg"},{"src":"04.jpg"},{"src":"05.jpg"},{"src":"06.jpg"},{"src":"07.jpg"}]}
    //当屏幕大小改变时从新执行瀑布流函数 达到从新适应的作用
    window.onresize=function(){
//      waterfall('content','box');
       setTimeout(function() {waterfall('content','box');}, 200);
    }
    window.onscroll=function(){
        if(checkScroll()){
            var oparent = document.getElementById('content');
            //将熏染的数据添加入html中
            for(var i=0;i<dataInt.data.length;i++){
                var obox = document.createElement("div");
                obox.className = "box";
                oparent.appendChild(obox);
                var opic = document.createElement("div");
                opic.className = "pic";
                obox.appendChild(opic);
                var oImg = document.createElement("img");
                oImg.src="img/"+dataInt.data[i].src;
                opic.appendChild(oImg);
            }
                waterfall('content','box');
        }
    }
 
}
function waterfall(parent,box){
    //将content下所有class box取出来
    var aParent = document.getElementById(parent);
    var aBox = getBclass(aParent,box);
     
    //获取盒子的宽度
    var aBoxW = aBox[0].offsetWidth;
    //用浏览器的可是宽度除以box宽度 得到列数
    var cols = Math.floor(document.documentElement.clientWidth/aBoxW);
    //设定 content的宽度 和居中
    aParent.style.cssText = 'width:'+aBoxW*cols+'px;height:auto;position: relative; margin:0 auto;padding-right:15px';
    //创建每一列的高度数组
    var hArr=[];
    for(var i=0; i<aBox.length;i++){
        aBox[i].style.cssText ='';
        if(i<cols){
            hArr.push(aBox[i].offsetHeight); 
        }else{
            var minH = Math.min.apply(null,hArr);
            var index = getMinIndex(hArr,minH);  //找出高最矮的 索引值
            //console.log(aBoxW);
            aBox[i].style.position = 'absolute';
            aBox[i].style.top = minH+'px';
            aBox[i].style.left = aBoxW*index+'px';
            hArr[index]+=aBox[i].offsetHeight;
        }
    }
}
//根据class获取到元素
function getBclass(parent,className){
    var boxarr = new Array(); //用来存储获取到的class
        //console.log(parent.prototype);
    allElement=parent.getElementsByTagName('*');
    for(var i=0;i<allElement.length;i++){
        if(allElement[i].className == className){
            boxarr.push(allElement[i]);
        }
    }
    return boxarr;
}
 
//找出高最矮的 索引值
function getMinIndex(arr,value){
    for(var i in arr){
        if (arr[i]==value){
            return i;
        }
    }
}
//建立一个检测轮轮滑动是否成立的函数  返回真假
function checkScroll(){
    var oparent = document.getElementById("content");
    var oBox = getBclass(oparent,'box');
    var lastoBoxTop = oBox[oBox.length-1].offsetTop+Math.floor(oBox[oBox.length-1].offsetHeight/2);
    //console.log(lastoBoxTop);
    var scrollTop = document.body.scrollTop||document.documentElement.scrollTop;
    var height = document.body.clientHeight||document.documentElement.clientHeight;
    //console.log(scrollTop);
    return(lastoBoxTop<scrollTop+height)?true:false;
}

css文件贴出来

复制代码代码如下:

*{margin: 0;padding: 0;}
body{background-color: #eee;}
.content{ 
    position: relative;
    }
.box{
    padding: 15px 0 0 15px;
    float: left;
}
.pic{
    padding: 10px;
    border: 1px solid #ccc;
    box-shadow: 0 0 5px #CCCCCC;
    border-radius: 5px;
    background: #fff;
}
.pic img{
    width: 220px;
    height: auto;
    border: 1px solid #eee;
}

html文件贴出来

复制代码代码如下:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title>javascript瀑布流</title>
        <link rel="stylesheet" type="text/css" href="css/pubuli.css"/>
        <script type="text/javascript" src="js/my.js" ></script>
    </head>
    <body>
        <div id="content">
            <div class="box">
                <div class="pic">
                <img src="img/01.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/02.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/03.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/04.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/05.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/06.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/07.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/08.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/09.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/10.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/11.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/12.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/13.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/14.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/15.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/16.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/17.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/18.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/19.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/20.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/21.jpg"/> 
                </div>
            </div>
            <div class="box">
                <div class="pic">
                <img src="img/22.jpg"/> 
                </div>
            </div>
        </div>
         
    </body>
</html>