详情案例可参看本网站改造后的效果，目前覆盖首页、栏目页、内容页界面。
核心JS代码：
<script type="text/javascript">
var fgm = {
on: function(element,type,handler) {
return element.addEventListener ? element.addEventListener(type,handler,false) : element.attachEvent("on" + type,handler)
},
bind: function(object,handler) {
return function() {
return handler.apply(object,arguments)
}
},
pageX: function(element) {
return element.offsetLeft + (element.offsetParent ? arguments.callee(element.offsetParent) : 0)
},
pageY: function(element) {
return element.offsetTop + (element.offsetParent ? arguments.callee(element.offsetParent) : 0)
},
hasClass: function(element,className) {
return new RegExp("(^|s)" + className + "(s|$)").test(element.className)
},
attr: function(element,attr,value) {
if(arguments.length == 2) {
return element.attributes[attr] ? element.attributes[attr].nodeValue : undefined
}
else if(arguments.length == 3) {
element.setAttribute(attr,value)
}
}
};
//延时加载
function LazyLoad(obj) {
this.lazy = typeof obj === "string" ? document.getElementById(obj) : obj;
this.aImg = this.lazy.getElementsByTagName("img");
this.fnLoad = fgm.bind(this,this.load);
this.load();
fgm.on(window,"scroll",this.fnLoad);
fgm.on(window,"resize",this.fnLoad);
}
LazyLoad.prototype = {
load: function() {
var iScrollTop = document.documentElement.scrollTop || document.body.scrollTop;
var iClientHeight = document.documentElement.clientHeight + iScrollTop;
var i = 0;
var aParent = [];
var oParent = null;
var iTop = 0;
var iBottom = 0;
var aNotLoaded = this.loaded(0);
if(this.loaded(1).length != this.aImg.length) {
for(i = 0; i < aNotLoaded.length; i++) {
oParent = aNotLoaded[i].parentElement || aNotLoaded[i].parentNode;
iTop = fgm.pageY(oParent);
iBottom = iTop + oParent.offsetHeight;
if((iTop > iScrollTop && iTop < iClientHeight) || (iBottom > iScrollTop && iBottom < iClientHeight)) {
aNotLoaded[i].src = fgm.attr(aNotLoaded[i],"data-img") || aNotLoaded[i].src;
aNotLoaded[i].className = "loaded";
}
}
}
},
loaded: function(status) {
var array = [];
var i = 0;
for(i = 0; i < this.aImg.length; i++)
eval("fgm.hasClass(this.aImg[i],"loaded")" + (!!status ? "&&" : "||") + "array.push(this.aImg[i])");
return array
}
};
//应用添加
fgm.on(window,"load",function () {new LazyLoad("box")});
fgm.on(window,function () {new LazyLoad("bxslider")});
</script>
在添加JS后直接在应用添加里面添加对应需要执行懒加载的区域即可，图片的代码调整为<img data-img="XXX"/>
内容页需要执行懒加载的话，参考：《dede手机站调用PC站图片》中函数的使用方法即可。需要帮助调整的，可在百家号贤话师兄处关注留言。
