本文實例為大家講解了javascript瀑布流代碼，即js頁面滾動延遲加載圖片，分享給大家供大家參考，具體代碼如下
<!DOCTYPE html><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>原生Js頁面滾動延遲加載圖片</title><style type="text/css">* { margin:0; padding:0}img.scrollLoading { border:1px solid #ccc; display:block; margin-top:10px;}</style></head><body><div id="content"></div></body></html><script type="text/javascript"> var _CalF = { $:function(object){//選擇器 if(object === undefined ) return; var getArr = function(name,tagName,attr){ var tagName = tagName || '*', eles = document.getElementsByTagName(tagName), clas = (typeof document.body.style.maxHeight === "undefined") ? "className" : "class";//ie6 attr = attr || clas, Arr = []; for(var i=0;i<eles.length;i++){ if(eles[i].getAttribute(attr)==name){ Arr.push(eles[i]); } } return Arr; }; if(object.indexOf('#') === 0){ //#id return document.getElementById(object.substring(1)); } else if(object.indexOf('.') === 0){ //.class return getArr(object.substring(1)); } else if(object.match(/=/g)){ //attr=name return getArr(object.substring(object.search(/=/g)+1),null,object.substring(0,object.search(/=/g))); } else if(object.match(/./g)){ //tagName.className return getArr(object.split('.')[1],object.split('.')[0]); } }, getPosition : function(obj) { //獲取元素在頁面里的位置和寬高 var top = 0, left = 0, width = obj.offsetWidth, height = obj.offsetHeight; while(obj.offsetParent){ top += obj.offsetTop; left += obj.offsetLeft; obj = obj.offsetParent; } return {"top":top,"left":left,"width":width,"height":height}; } }; //添加圖片list var _temp = []; for (var i = 1; i < 21; i ++) { _temp.push('<img class="scrollLoading" data-src="http://images.cnblogs.com/cnblogs_com/Darren_code/311197/o_' + i + '.jpg" src="http://images.cnitblog.com/blog/150659/201306/23160223-c81dd9aa9a2a4071a47b0ced2c9118bc.gif" /><br />圖片' + i); } _CalF.$("#content").innerHTML = _temp.join(""); function scrollLoad(){ this.init.apply(this, arguments); } scrollLoad.prototype ={ init : function(className){ var className = "img."+className, imgs = _CalF.$(className), that = this; this.imgs = imgs; that.loadImg(); window.onscroll = function(){ that.time = setTimeout(function(){ that.loadImg(); },400); } }, loadImg : function(){ var imgs = this.imgs.reverse(), //獲取數組翻轉 len = imgs.length; if(imgs.length===0){ clearTimeout(this.time); return; } for(var j=len-1;j>=0;j--){ //遞減 var img = imgs[j], imgTop = _CalF.getPosition(img).top, imgSrc = img.getAttribute("data-src"), offsetPage = window.pageYOffset ? window.pageYOffset : window.document.documentElement.scrollTop,//滾動條的top值 bodyHeight = document.documentElement.clientHeight; //body的高度 if((offsetPage+bodyHeight/2) > (imgTop-bodyHeight/2)){ img.src = imgSrc; this.imgs.splice(j,1); } } } } var img1 = new scrollLoad("scrollLoading"); </script>希望本文所述對大家學習javascript程序設計有所幫助。
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