function easyViewImg(classNameArr,expandWidthParam,expandHeightParam){

//设置需执行方法的所有img的classname

var imgClassName = '';

if(!classNameArr) imgClassName = 'img';

if(typeof classNameArr === "string") imgClassName = '.'+classNameArr;

if(Array.isArray(classNameArr)){

for (var i = 0; i < classNameArr.length; i++) {

imgClassName+='.'+classNameArr[i];

if(i < classNameArr.length-1) imgClassName +=",";

}

}

//设置默认图片放大系数

if(!expandWidthParam) expandWidthParam = 1.5;

if(!expandHeightParam) expandHeightParam = 1.5;

//添加执行方法

$(document).on('click',imgClassName,function(){

//获取图片路径

var that = this;

var url = $(that)[0].src;

var imgHeight = $(that)[0].height * expandHeightParam;

var imgWidth = $(that)[0].width * expandWidthParam;

var screenHeight = window.screen.height;

var screenWidth = window.screen.width;

//若放大后的图片大小超过了当前屏幕的大小，则设置合适的图片大小

if(imgHeight > screenHeight*0.8 || imgWidth > screenWidth *0.8){

if((imgWidth/imgHeight) > screenWidth/screenHeight){

imgWidth = screenWidth*0.8;

imgHeight = imgHeight * imgWidth / ($(that)[0].width * expandWidthParam);

}else {

imgHeight = screenHeight*0.8;

imgWidth = imgHeight * imgWidth / ($(that)[0].height * expandHeightParam);

}

}

var div = document.createElement("div");

div.className = 'shade_temp_div';

div.style.cssText = "background:#000000;opacity:0.3;position:absolute;z-index:20190226;left:0px;top:0px;width:"+$(document).width()+"px;height:"+$(document).height()+"px;text-align:center;";

document.body.insertBefore(div,document.body.lastChild);

var imgDiv = document.createElement("div");

imgDiv.className = 'shade_temp_div shade_temp_div_img';

var left = (screenWidth - imgWidth)/2;

var top = (screenHeight - imgHeight)/2 - 80;

imgDiv.style.cssText = 'text-align: center;position: fixed;left: '+left+'px;top: '

+top+'px;z-index: 20190227;width: auto;height: auto;box-shadow:0px 0px 50px rgba(0,0,0,0.6),0 0 100px rgba(0,0,0,0.1)';

imgDiv.innerHTML='<img src="'+url+'" style="width:'+imgWidth+'px;height:'+imgHeight+'px;"/>';

document.body.insertBefore(imgDiv,document.body.lastChild);

$(".shade_temp_div_img").hide(0);

$(".shade_temp_div_img").fadeIn(500);

sessionStorage.setItem("hidden_img_sign",(screenHeight - imgHeight)/2- 80);

});

$(window).bind("scroll",function(){

var scrollTop = $(this).scrollTop();

var top = sessionStorage.getItem("hidden_img_sign");

if(top) $(".shade_temp_div_img").css("top",parseFloat(top)+"px");

});

}

$(document).on('click','.shade_temp_div',function(){

$('.shade_temp_div').hide();

$(".shade_temp_div").remove();

sessionStorage.setItem("hidden_img_sign",null);

});