js和jquery如何获取图片真实的宽度和高度

var _w = parseInt($(window).width());//获取浏览器的宽度$(".new_mess_c img").each(function(i){var img = $(this);var realWidth;//真实的宽度var realHeight;//真实的高度//这里做下说明，$("<img/>")这里是创建一个临时的img标签，类似js创建一个new Image()对象！$("<img/>").attr("src", $(img).attr("src")).load(function() {/*如果要获取图片的真实的宽度和高度有三点必须注意1、需要创建一个image对象：如这里的$("<img/>")2、指定图片的src路径3、一定要在图片加载完成后执行如.load()函数里执行*/realWidth = this.width;realHeight = this.height;//如果真实的宽度大于浏览器的宽度就按照100%显示if(realWidth>=_w){$(img).css("width","100%").css("height","auto");}else{//如果小于浏览器的宽度按照原尺寸显示$(img).css("width",realWidth+'px').css("height",realHeight+'px');}});});

window.onload = function(){function getViewSize() {//获取浏览器视口的宽高return {"w": window['innerWidth'] || document.documentElement.clientWidth,(www.VeVB.COm) "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';}}}}