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用js实现瀑布流的一种简单方法

现在说瀑布流式布局似乎有点晚了,但是每一项技术都是向着“精”和“简”的方向在不断发展,在发展到极致之前,需要一个相当漫长的过程,因此,从这个角度来说,当瀑布流被应用得越来越多的时候,反而更应该讨论它,讨论如何将它改善。。。

下面奉上一则用JS实现瀑布流的方法,望批评。

 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>瀑布流布局测试</title>
<style>
body {
    background-color: #eee;
    font-size: 84%;
    text-align: justify;
}
.column {
    display: inline-block;
    vertical-align: top;
}
.pic_a {
    display: block;
    padding: 5px;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    background-color: #fff;
    text-decoration: none;
}
.pic_a img {
    display: block;
    margin: 0 auto 5px;
    border: 0;
    vertical-align: bottom;
}
.pic_a strong {
    color: #333;
}
</style>
</head>

<body>
<div id="container"></div>
<script>
var waterFall = {
    container: document.getElementById("container"),
    columnNumber: 1,
    columnWidth: 210,
    // P_001.jpg ~ P_160.jpg
    rootImage: "test/",
    indexImage: 0,
    
    scrollTop: document.documentElement.scrollTop || document.body.scrollTop,
    detectLeft: 0,
    
    loadFinish: false,
    
    // 返回固定格式的图片名
    getIndex: function() {
        var index = this.indexImage;
        if (index < 10) {
            index = "00" + index;    
        } else if (index < 100) {
            index = "0" + index;    
        }
        return index;
    },
    
    // 是否滚动载入的检测
    appendDetect: function() {
        var start = 0;
        for (start; start < this.columnNumber; start++) {
            var eleColumn = document.getElementById("waterFallColumn_" + start);
            if (eleColumn && !this.loadFinish) {
                if (eleColumn.offsetTop + eleColumn.clientHeight < this.scrollTop + (window.innerHeight || document.documentElement.clientHeight)) {
                    this.append(eleColumn);
                }
            }            
        }
        
        return this;
    },
    
    // 滚动载入
    append: function(column) {
        this.indexImage += 1;
        var html = '', index = this.getIndex(), imgUrl = this.rootImage + "P_" + index + ".jpg";
        
        // 图片尺寸
        var aEle = document.createElement("a");
        aEle.href = "###";
        aEle.className = "pic_a";
        aEle.innerHTML = '<img src="'+ imgUrl +'" /><strong>'+ index +'</strong>';
        column.appendChild(aEle);
        
        if (index >= 160) {
            //alert("图片加载光光了!");
            this.loadFinish = true;
        }
        
        return this;
    },
    
    // 页面加载初始创建
    create: function() {
        this.columnNumber = Math.floor(document.body.clientWidth / this.columnWidth);
        
        var start = 0, htmlColumn = '', self = this;
        for (start; start < this.columnNumber; start+=1) {
            htmlColumn = htmlColumn + '<span id="waterFallColumn_'+ start +'" class="column" style="width:'+ this.columnWidth +'px;">'+ 
                function() {
                    var html = '', i = 0;
                    for (i=0; i<5; i+=1) {
                        self.indexImage = start + self.columnNumber * i;
                        var index = self.getIndex();
                        html = html + '<a href="###" class="pic_a"><img src="'+ self.rootImage + "P_" + index +'.jpg" /><strong>'+ index +'</strong></a>';
                    }
                    return html;    
                }() +
            '</span> ';    
        }
        htmlColumn += '<span id="waterFallDetect" class="column" style="width:'+ this.columnWidth +'px;"></span>';
        
        this.container.innerHTML = htmlColumn;
        
        this.detectLeft = document.getElementById("waterFallDetect").offsetLeft;
        return this;
    },
    
    refresh: function() {
        var arrHtml = [], arrTemp = [], htmlAll = '', start = 0, maxLength = 0;
        for (start; start < this.columnNumber; start+=1) {
            var arrColumn = document.getElementById("waterFallColumn_" + start).innerHTML.match(/<a(?:.|\n|\r|\s)*?a>/gi);
            if (arrColumn) {
                maxLength = Math.max(maxLength, arrColumn.length);
                // arrTemp是一个二维数组
                arrTemp.push(arrColumn);
            }
        }
        
        // 需要重新排序
        var lengthStart, arrStart;
        for (lengthStart = 0; lengthStart<maxLength; lengthStart++) {
            for (arrStart = 0; arrStart<this.columnNumber; arrStart++) {
                if (arrTemp[arrStart][lengthStart]) {
                    arrHtml.push(arrTemp[arrStart][lengthStart]);    
                }
            }    
        }
        
        
        if (arrHtml && arrHtml.length !== 0) {
            // 新栏个数        
            this.columnNumber = Math.floor(document.body.clientWidth / this.columnWidth);
            
            // 计算每列的行数
            // 向下取整
            var line = Math.floor(arrHtml.length / this.columnNumber);
            
            // 重新组装HTML
            var newStart = 0, htmlColumn = '', self = this;
            for (newStart; newStart < this.columnNumber; newStart+=1) {
                htmlColumn = htmlColumn + '<span id="waterFallColumn_'+ newStart +'" class="column" style="width:'+ this.columnWidth +'px;">'+ 
                    function() {
                        var html = '', i = 0;
                        for (i=0; i<line; i+=1) {
                            html += arrHtml[newStart + self.columnNumber * i];
                        }
                        // 是否补足余数
                        html = html + (arrHtml[newStart + self.columnNumber * line] || '');
                        
                        return html;    
                    }() +
                '</span> ';    
            }
            htmlColumn += '<span id="waterFallDetect" class="column" style="width:'+ this.columnWidth +'px;"></span>';
        
            this.container.innerHTML = htmlColumn;
            
            this.detectLeft = document.getElementById("waterFallDetect").offsetLeft;
            
            // 检测
            this.appendDetect();
        }
        return this;
    },
    
    // 滚动加载
    scroll: function() {
        var self = this;
        window.onscroll = function() {
            // 为提高性能,滚动前后距离大于100像素再处理
            var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
            if (!this.loadFinish && Math.abs(scrollTop - self.scrollTop) > 100) {
                self.scrollTop = scrollTop;
                self.appendDetect();    
            }
            
        };
        return this;
    },
    
    // 浏览器窗口大小变换
    resize: function() {
        var self = this;
        window.onresize = function() {
            var eleDetect = document.getElementById("waterFallDetect"), detectLeft = eleDetect && eleDetect.offsetLeft;
            if (detectLeft && Math.abs(detectLeft - self.detectLeft) > 50) {
                // 检测标签偏移异常,认为布局要改变
                self.refresh();    
            }
        };
        return this;
    },
    init: function() {
        if (this.container) {
            this.create().scroll().resize();    
        }
    }
};
waterFall.init();
</script>
</body>
</html>

 

来源:http://blog.csdn.net/buyingfei8888/article/details/14051805

posted on 2013-11-03 08:34  爱莲学堂  阅读(453)  评论(0编辑  收藏

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