二次开发，向dom中插入容器，完成点击显示大图。

//绑定selectchange事件 ， 这个是项目中 弹出页面加载完成时触发的事件， 无太大关系。
function oninitfillforms(fillforms){
fillforms.on("loadform",function(event){ 
debugger;
loadimg()
emptyClick();
setUploadDefaultImage();
UploadImage();
})


createImgDiv();
};
/* 获取被点击要下载的图片，并设置无图片时禁止点击*/
function loadimg(){
$(document).on("mouseenter",".sz-commons-fileupload-image-item",function(){
var imgsrc=$(this).find('.sz-commons-fileupload-image-image').attr("src");
if(imgsrc){
var addimg=$(this).siblings('.sz-commons-fileupload-image-buttons').find('.lianjie');
addimg.attr('href',imgsrc);
addimg.attr('download');
}else{
$(this).siblings('.sz-commons-fileupload-image-buttons').find('.lianjie').removeAttr('href');
}
});
};
/*解决图片闪烁bug*/
$(document).on("click",".sz-commons-fileupload-image-item",function(){
var imgsrc=$(this).find('.sz-commons-fileupload-image-image').attr("src");
if(imgsrc){
$('.bigimg').show();
        $('.bigimg img').attr("src",imgsrc);
}
});
$(document).on("mouseenter",".bigimg",function(){
    $('.bigimg').show();
});
$(document).on("mouseleave",".sz-commons-fileupload-image-item",function(){
$('.bigimg').hide();
});
$(document).on("mouseleave",".bigimg",function(){
$('.bigimg').hide();
});
$(document).on("mouseenter",".bigimg",function(){
    $('.bigimg').show();
});
$(document).on("mouseleave",".sz-commons-fileupload-image-item",function(){
$('.bigimg').hide();
});
$(document).on("mouseleave",".bigimg",function(){
$('.bigimg').hide();
});
/*设置图片框，将系统自动默认点击事件清空*/
function emptyClick(){
$('.sz-commons-fileupload-image-item').attr("onclick", "");
};
/*增加大图容器*/
function createImgDiv() {
   // debugger;
    var Bigimg= document.createElement("div");
    Bigimg.setAttribute("class",'bigimg'); 
    Bigimg.style.position = 'absolute'; 
    Bigimg.style.top = '130px'; 
    Bigimg.style.left = '50%'; 
    Bigimg.style.margin = '0 0 0 -400px';
    Bigimg.style.display = 'none'; 
Bigimg.style.zIndex = 1000009;
//var a=document.createElement("a");
//a.setAttribute("class",'lianjie');
    var img= document.createElement("img"); 
   img.style.display = 'block'; 
img.style.maxWidth = '100%'; 
      img.style.maxHeight = '400px'; 
        img.style.margin = '0 auto';
//a.appendChild(img);
Bigimg.appendChild(img);
    document.body.appendChild(Bigimg);
}
/*创建下载图片按钮*/
function UploadImage(){
debugger;
var father= document.getElementsByClassName('sz-commons-fileupload-image-buttons');
for(var i=0;i<father.length;i++){
var span =document.createElement("span");
span.style.width='16px';
span.style.height='16px';
span.style.display='inline-block';
span.style.background='url(/meta/ZLreport:/collections/WL/WLZL/WL03/ZLSJBG/resources/images/download.png)';
var a=document.createElement("a");
a.setAttribute("class",'lianjie');
a.appendChild(span);
father[i].appendChild(a);
}
};
/*设置上传默认背景图片*/
function setUploadDefaultImage() {
$(".sz-commons-fileupload-image-default").css("background", "url(/meta/ZLreport:/collections/WL/WLZL/WL03/ZLSJBG/resources/images/moren.png) no-repeat center center")
}