window.onload = function(){ function getViewSize() {//获取浏览器视口的宽高 return { "w": window[‘innerWidth‘] || document.documentElement.clientWidth, () "h": window[‘innerHeight‘] || document.documentElement.clientHeight } } function getFullSize() {//获取浏览器最大的宽度 var w = Math.max(document.documentElement.clientWidth, document.body.clientWidth) + Math.max(document.documentElement.scrollLeft, document.body.scrollLeft); var h = Math.max(document.documentElement.clientHeight, document.body.clientHeight) + Math.max(document.documentElement.scrollTop, document.body.scrollTop); w = Math.max(document.documentElement.scrollWidth, w); h = Math.max(document.documentElement.scrollHeight, h); return { "w": w, "h": h }; } var _sv_w = getViewSize()["w"]; var _sf_w = getFullSize()["w"]; var _w = _sv_w;//这里用视口的宽度，具体视情况 var Imgarray = document.getElementsByTagName("img"); var realWidth;//真实的宽度 var realHeight;//真实的高度 for(var i =0;i<Imgarray.length;i++){ var imgtemp = new Image();//创建一个image对象 imgtemp.src = Imgarray[i].src; imgtemp.index = i;//指定一个检索值，用于确定是哪张图 imgtemp.onload = function(){//图片加载完成后执行 var _stemp = this;//将当前指针复制给新的变量，不然会导致变量共用 realWidth = this.width; realHeight = this.height; if(realWidth >=_w ) { Imgarray[_stemp.index].style.width = _w+‘px‘; Imgarray[_stemp.index].style.height = ‘auto‘; } else{ Imgarray[_stemp.index].style.width = realWidth+‘px‘; Imgarray[_stemp.index].style.height = realHeight+‘px‘; } } } }