代码改变世界

（转）页面滚动图片加载

2011-07-22 16:22  音乐让我说  阅读(256)  评论(0)  编辑  收藏  举报

代码如下：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>页面滚动图片加载</title> 
<style> 
body{text-align:center;}
.list{margin-bottom:40px;}
</style> 
</head> 
<body> 
<div> 
    <div> 
        <h1>页面滚动图片加载</h1> 
        <div>这些书本人大多都看过，其中几本是前端必看，想了解可以去本人以前的文章 - <a target="_blank" href="http://www.cnblogs.com/Darren_code/archive/2011/06/29/javascript-learn.html">《说说我的web前端之路,分享些前端的好书》</a>看看。<br /><br />最后一本目前正在看，有种看小说的感觉，看的很过瘾，推荐给大家..</div><br /><br />
        <div id="content"> 
			<script type="text/javascript">
			    var main = "";
			    for (var i = 1; i < 21; i ++) {
			        main += '<div class="list"><img class="scrollLoading" xSrc="http://images.cnblogs.com/cnblogs_com/Darren_code/311197/o_' + i + '.jpg" src="http://images.cnblogs.com/cnblogs_com/Darren_code/302725/o_pixel.gif" width="200" height="250" style="background:url(http://images.cnblogs.com/cnblogs_com/Darren_code/302725/o_108.gif) no-repeat center;" /><br />图片' + i + '</div>';
			    }
			    document.getElementById("content").innerHTML = main;
			</script> 
        </div> 
    </div> 
</div>
<script type="text/javascript">
    var scrollLoad = function (options) {
        var defaults = (arguments.length == 0) ? { src: 'xSrc', time: 300} : { src: options.src || 'xSrc', time: options.time ||300};
        var camelize = function (s) {
            return s.replace(/-(\w)/g, function (strMatch, p1) {
                return p1.toUpperCase();
            });
        };
        this.getStyle = function (element, property) {
            if (arguments.length != 2) return false;
            var value = element.style[camelize(property)];
            if (!value) {
                if (document.defaultView && document.defaultView.getComputedStyle) {
                    var css = document.defaultView.getComputedStyle(element, null);
                    value = css ? css.getPropertyValue(property) : null;
                } else if (element.currentStyle) {
                    value = element.currentStyle[camelize(property)];
                }
            }
            return value == 'auto' ? '' : value;
        };
        var _init = function () {
            var offsetPage = window.pageYOffset ? window.pageYOffset : window.document.documentElement.scrollTop,
                offsetWindow = offsetPage + Number(window.innerHeight ? window.innerHeight : document.documentElement.clientHeight),
                docImg = document.images,
                _len = docImg.length;
            if (!_len) return false;
            for (var i = 0; i < _len; i++) {
                var attrSrc = docImg[i].getAttribute(defaults.src),
                    o = docImg[i], tag = o.nodeName.toLowerCase();
                if (o) {
                    postPage = o.getBoundingClientRect().top + window.document.documentElement.scrollTop + window.document.body.scrollTop; postWindow = postPage + Number(this.getStyle(o, 'height').replace('px', ''));
                    if ((postPage > offsetPage && postPage < offsetWindow) || (postWindow > offsetPage && postWindow < offsetWindow)) {
                        if (tag === "img" && attrSrc !== null) {
                            o.setAttribute("src", attrSrc);
                        }
                        o = null;
                    }
                }
            };
            window.onscroll = function () {
                setTimeout(function () {
                    _init();
                }, defaults.time);
            }
        };
        return _init();
    };
    scrollLoad();
</script> 
</body> 
</html>

转载自：http://www.cnblogs.com/Darren_code/archive/2011/07/21/LoadImage.html

谢谢浏览！