最近項(xiàng)目使用到了“懶加載”，現(xiàn)在更新一般，因?yàn)槠綍r(shí)主要使移動(dòng)端的開發(fā)所以庫文件使用的是zepto.js 。當(dāng)然也可以和jQuery 通用。
代碼如下：
/** * Created by zhiqiang on 2015/10/14. * hpuhouzhiqiang@gmail.com * 圖片的懶加載 **/function loadImgLazy(node) { var lazyNode = $('[node-type=imglazy]', node), mobileHeight, lazyOffSetHeight, tempHeight, currentNodeTop, imgObject, imgDataSrc, localUrl; localUrl = location.href; // 獲取當(dāng)前瀏覽器可視區(qū)域的高度 mobileHeight = $(window).height(); return function(co) { var conf = { 'loadfirst': true, 'loadimg': true }; for (var item in conf) { if (item in co) { conf[item] = co[item]; } } var that = {}; var _this = {}; /** * [replaceImgSrc 動(dòng)態(tài)替換節(jié)點(diǎn)中的src] * @param {[type]} tempObject [description] * @return {[type]} [description] */ _this.replaceImgSrc = function(tempObject) { var srcValue; $.each(tempObject, function(i, item) { imgObject = $(item).find('img[data-lazysrc]'); imgObject.each(function(i) { imgDataSrc = $(this).attr('data-lazysrc'); srcValue = $(this).attr('src'); if (srcValue == '#') { if (imgDataSrc) { $(this).attr('src', imgDataSrc); $(this).removeAttr('data-lazysrc'); } } }); }); }; /** * 首屏判斷屏幕上是否出現(xiàn)imglazy節(jié)點(diǎn)，有的話就加載圖片 * @param {[type]} i) { currentNodeTop [description] * @return {[type]} [description] */ _this.loadFirstScreen = function() { if (conf.loadfirst) { lazyNode.each(function(i) { currentNodeTop = $(this).offset().top; if (currentNodeTop < mobileHeight + 800) { _this.replaceImgSrc($(this)); } }); } }; //當(dāng)加載過首屏以后按照隊(duì)列加載圖片 _this.loadImg = function() { if (conf.loadimg) { $(window).on('scroll', function() { var imgLazyList = $('[node-type=imglazy]', node); for (var i = 0; i < 5; i++) { _this.replaceImgSrc(imgLazyList.eq(i)); } }); } }; that = { replaceImgSrc: _this.replaceImgSrc(), mobileHeight: mobileHeight, objIsEmpty: function(obj) { for (var item in obj) { return false; } return true; }, destory: function() { if (_this) { $.each(_this, function(i, item) { if (item && item.destory) { item.destory(); } }); _this = null; } $(window).off('scroll'); } }; return that; };} 希望本文對(duì)大家學(xué)習(xí)javascript圖片懶加載有所幫助。
