console 命令行工具 X clear
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<!doctype html public "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="utf-8">
<head>
<title> 代码实例：拖动对象 Drag Object (兼容:IE、Firefox、Opera ... )</title>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<style>
.dragAble {position:relative;cursor:move;}
  .img-con {
    	position:relative;
        width: 713px;
        height: 455px;
        overflow: hidden;
        border: 1px solid red;
		
    }
</style>
<script language="javascript">
//放大缩小
 window.onload = function() {
        var oImg = document.getElementsByTagName("img")[0];
 
        function fnWheel(obj, fncc) {
            obj.onmousewheel = fn;
            if (obj.addEventListener) {
                obj.addEventListener('DOMMouseScroll', fn, false);
            }
 
            function fn(ev) {
                var oEvent = ev || window.event;
                var down = true;
 
                if (oEvent.detail) {
                    down = oEvent.detail > 0
                } else {
                    down = oEvent.wheelDelta < 0
                }
 
                if (fncc) {
                    fncc.call(this, down, oEvent);
                }
 
                if (oEvent.preventDefault) {
                    oEvent.preventDefault();
                }
 
                return false;
            }
 
 
        };
        fnWheel(oImg, function(down, oEvent) {
 
            var oldWidth = this.offsetWidth;
            var oldHeight = this.offsetHeight;
            var oldLeft = this.offsetLeft;
            var oldTop = this.offsetTop;
 
            var scaleX = (oEvent.clientX - oldLeft) / oldWidth; //比例
            var scaleY = (oEvent.clientY - oldTop) / oldHeight;
 
            if (down) {
                this.style.width = this.offsetWidth * 0.9 + "px";
                this.style.height = this.offsetHeight * 0.9 + "px";
            } else {
                this.style.width = this.offsetWidth * 1.1 + "px";
                this.style.height = this.offsetHeight * 1.1 + "px";
            }
 
            var newWidth = this.offsetWidth;
            var newHeight = this.offsetHeight;
 
            this.style.left = oldLeft - scaleX * (newWidth - oldWidth) + "px";
            this.style.top = oldTop - scaleY * (newHeight - oldHeight) + "px";
        });
    }
<!--
//拖拽
var ie=document.all;
var nn6=document.getElementByIdx&&!document.all;
var isdrag=false;
var y,x;
var oDragObj;
function moveMouse(e) {
 if (isdrag) {
 oDragObj.style.top  =  (nn6 ? nTY + e.clientY - y : nTY + event.clientY - y)+"px";
 oDragObj.style.left  =  (nn6 ? nTX + e.clientX - x : nTX + event.clientX - x)+"px";
 return false;
 }
}
function initDrag(e) {
 var oDragHandle = nn6 ? e.target : event.srcElement;
 var topElement = "HTML";
 while (oDragHandle.tagName != topElement && oDragHandle.className != "dragAble") {
 oDragHandle = nn6 ? oDragHandle.parentNode : oDragHandle.parentElement;
 }
 if (oDragHandle.className=="dragAble") {
 isdrag = true;
 oDragObj = oDragHandle;
 nTY = parseInt(oDragObj.style.top+0);
 y = nn6 ? e.clientY : event.clientY;
 nTX = parseInt(oDragObj.style.left+0);
 x = nn6 ? e.clientX : event.clientX;
 document.onmousemove=moveMouse;
 return false;
 }
}
document.onmousedown=initDrag;
document.onmouseup=new Function("isdrag=false");
//-->
</script>
</head>
<body>
 <p class="img-con"><img src="https://www.baidu.com/img/flexible/logo/pc/result.png" class="dragAble" /></p>
</body>
</html>
本项目引用的自定义外部资源

jquery.min.js