做项目的时候使用到一个图片浏览的插件jQuery.iviewer，链接地址：http://www.jq22.com/jquery-info4580
效果如下：
但是应用的时候出现不能滚动放大缩小的问题，查看代码的时候发现封装的滚轮判断事件有点问题，返回的delta都为0，然后对jquery.iviewer.js的代码做了一些修改：
1、添加函数addWheelEvent来判断滚动方式
/** ???* ??nomousewheel ???**/ ???// 兼容所有浏览器 ???addWheelEvent: function (obj,efn){ ???????//判断IE8还是非IE8 ???????if(document.addEventListener){ ???????????//火狐还是非火狐 ???????????var oDiv = document.createElement("div"); ???????????if(oDiv.onmousewheel === null){ ???????????????obj.addEventListener("mousewheel",fn,false); ???????????}else{ ???????????????obj.addEventListener("DOMMouseScroll", fn, false); ???????????} ???????}else{ ???????????obj.attachEvent("onmousewheel", fn); ???????} ???????function fn(ev){ ???????????ev = ev || window.event; ???????????var d = ev.wheelDelta/120 || -ev.detail/3; ???????????var rs = efn.call(obj,ev,d); ???????????if(rs === false){//禁止滚动条默认事件 ???????????????ev.preventDefault && ev.preventDefault(); ???????????????return false; ???????????} ???????} ???},2、修改_create函数中的滚动事件：注释‘mousewheel.iviewer‘方法，改用前面新增的方法addWheelEvent
if (this.options.mousewheel) { ???????????// this.container.bind(‘mousewheel.iviewer‘, function(ev, delta) ???????????var obj = this.container.get(0);//将jQuery对象转化为DOM对象 ???????????this.addWheelEvent(obj,function(ev,delta)//使用新增方法 ???????????{ ???????????????//this event is there instead of containing div, because ???????????????//at opera it triggers many times on div ???????????????????????????????var zoom = (delta > 0)?1:-1, ???????????????container_offset = me.container.offset(), ???????????????mouse_pos = { ???????????????????//jquery.mousewheel 3.1.0 uses strange MozMousePixelScroll event ???????????????????//which is not being fixed by jQuery.Event ???????????????????x: (ev.pageX || ev.originalEvent.pageX) - container_offset.left, ???????????????????y: (ev.pageY || ev.originalEvent.pageX) - container_offset.top ???????????????}; ???????????????me.zoom_by(zoom, mouse_pos); ???????????????return false; ???????????});【插件】jQuery.iviewer----图片浏览、放大、缩小、全屏
原文地址：https://www.cnblogs.com/qiuyueding/p/8297654.html