需求背景：购物网站中的商品局部放大：
代码：
html:
<div class="Pro_Detleft">
<div class="detail-itemsummary-imageviewer">
<div id="middlePicRemark" class="middlePicRemark"> <img id="imgGoodsPic" alt="" src="images/20141009154623153.jpg" style="width:950px; height:950px; display:block;position: relative"></div>
<div id="middlePicBox" class="middlePicBox">
<span id="BigViewImage" class="jqzoom" style="outline-style: none; cursor: crosshair; display: block; position: relative; height: 396px; width: 396px;"><img id="" style="width: 396px; height: 396px; position: absolute; top: 0px; left: 0px;"
src="images/20141009154623153.jpg">
<div class=‘jqZoomPup‘ style=‘height:166.32px;width: 214.240837696335px;border-width: 1px;visibility: hidden;position: absolute;‘>
</div></span>
</div>
css:
.middlePicRemark {
position: absolute;
top: 0;
left: 0;
width: 244px;
z-index: 1;
line-height: 18px;
text-align: center;
padding: 3px;
background-color: #f3f3f3;
border: 1px #999 solid;
display: none;
}
.middlePicBox {
clear: both;
PADDING-BOTTOM: 0;
HEIGHT: 396px;
TEXT-ALIGN: center;
border: 1px solid #E3E3E3;
position: relative;
}
.middlePicBox i.F_goods_xg {
display: block;
width: 77px;
height: 77px;
position: absolute;
top: 28px;
left: 28px;
z-index: 5;
}
.middlePicBox {
clear: both;
PADDING-BOTTOM: 0;
HEIGHT: 396px;
TEXT-ALIGN: center;
border: 1px solid #E3E3E3;
position: relative;
}
.jqZoomPup {
overflow: hidden;
background-color: #FFF;
-moz-opacity: 0.6;
opacity: 0.6;
filter: alpha(opacity = 60);
z-index: 10;
border-color: #e3e3e3;
border-style: solid;
cursor: crosshair;
}
js:
//鼠标在大图上移动时局部放大
/*
* 算法思路是用两个图片，一个为鼠标在其上移动的小图，另一个为大图，动态获取鼠标的位置，在小图上的偏移量成比例的移动大图，使其部分显示在div中达到放大效果
*
* */
$("#BigViewImage").mousemove(function(e){
var divObj=document.getElementById("middlePicBox");//获取外层span在整个页面的偏移量
var curX= e.pageX-GetObjPos(divObj)[‘x‘]; //获取鼠标相对于大图片左上角的偏移量
var curY= e.pageY-GetObjPos(divObj)[‘y‘];
if(curX<107.12)curX=107.12; //如果小图片左上角到达大图片左上角，则停止移动
if(curX>288.88)curX=288.88;
if(curY<83.16)curY=83.16;
if(curY>312.84)curY=312.84;
var percentX=(curX-107.12)/396;
var percentY=(curY-83.16)/396; //当前小矩形框的左上角偏移量相对于图片的横向比例
var BigViewOffsetX=percentX*950; //计算出右边放大图应该放大的偏移量
var BigViewOffsetY=percentY*950;
$("#middlePicRemark").css(‘display‘,‘block‘);
$(‘.jqZoomPup‘).css(‘left‘,curX-107.12+‘px‘);
$(‘.jqZoomPup‘).css(‘top‘,curY-83.16+‘px‘);
$(".jqZoomPup").css(‘visibility‘,‘visible‘);
$("#imgGoodsPic").css(‘left‘,0-BigViewOffsetX+‘px‘);
$("#imgGoodsPic").css(‘top‘,0-BigViewOffsetY+‘px‘);
}).mouseout(function(){
$(".jqZoomPup").css(‘visibility‘,‘hidden‘);
$("#middlePicRemark").css(‘display‘,‘none‘);
});