<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
*{
margin:0;
padding:0;
}
#smPic{
float:left;
position:relative;
400px;
height:225px;
margin-left:100px;
margin-top:100px;
}
#smPic img{
400px;
height:225px;
}
#smPic #drag{
position:absolute;
left:0;
top:0;
background:rgba(0,0,0,0.5);
80px;
height:45px;
display:none;
}
#bigBox{
float:left;
position:relative;
400px;
height:225px;
overflow:hidden;
display:none;
margin-top:100px;
}
#bigPic{
position:absolute;
left:0;
top:0;
2000px;
height:1125px;
}
</style>
</head>
<body>
<div id="smPic">
<img src="img/1.jpg" alt="" />
<div id="drag"></div>
</div>
<div id="bigBox">
<img src="img/1.jpg" alt="" id="bigPic" />
</div>
<script src="js/jquery-2.2.1.min.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
$("#smPic").bind({
"mouseover":function(){
$("#drag").css("display","block");
$("#bigBox").css("display","block");
},
"mousemove":function(e){
var event = e||window.event;
var oLeft = event.pageX-($("#drag").outerWidth()/2);
var oTop = event.pageY-($("#drag").outerHeight()/2);
var smPicLeft = $("#smPic").offset().left;
var smPicTop = $("#smPic").offset().top;
var nowLeft = oLeft - smPicLeft;
var nowTop = oTop - smPicTop;
console.log(nowLeft)
if(nowLeft<=0){
nowLeft = 0;
}else if(nowLeft>=($("#smPic").outerWidth()-$("#drag").outerWidth())){
nowLeft = $("#smPic").outerWidth()-$("#drag").outerWidth();
}
if(nowTop<=0){
nowTop = 0;
}else if(nowTop>=($("#smPic").outerHeight()-$("#drag").outerHeight())){
nowTop = $("#smPic").outerHeight()-$("#drag").outerHeight();
}
$("#drag").css({"left":nowLeft,"top":nowTop});
$("#bigPic").css({"left":(-nowLeft*5),"top":(-nowTop*5)});
}
,
"mouseout":function(){
$("#drag").css("display","none");
$("#bigBox").css("display","none");
}
})
</script>
</body>
</html>