用javascript放大图片局部

用javascript放大图片局部

刚才解答论坛上一个帖子顺手写的代码，贴出来免得下次找不着。

< html >
< head >
< title > emu </ title >
</ head >
< body >
< BR >
原图： < BR >
< img  src ="http://img.pconline.com.cn/images/photo2/839980/1118509777696.JPG"  onmousemove ="zoom()"  id =srcImg>
<BR >
局部放大图： < BR >
< div  style ="overflow:hidden" >< img  id =zoomImg></div>

<SCRIPT LANGUAGE ="JavaScript" >
<!--
zoomImg.src = srcImg.src;
srcImg.height = srcImg.height/2;
var zoomRate = 5;
zoomImg.height = srcImg.height*zoomRate;
zoomImg.parentNode.style.width = srcImg.width;
zoomImg.parentNode.style.height = srcImg.height;
function zoom(){
var elm = event.srcElement;
h = elm.offsetHeight/zoomRate/2;
w = elm.offsetWidth/zoomRate/2;
var x = event.x-elm.offsetLeft;
x=x<(elm.offsetWidth-w)?x<w?w:x:elm.offsetWidth-w;
zoomImg.style.marginLeft=(w-x)*zoomRate;
var y = event.y-elm.offsetTop;
y=y<(elm.offsetHeight-h)?y<h?h:y:elm.offsetHeight-h;
zoomImg.style.marginTop=(h-y)*zoomRate;
}
// -->
</ SCRIPT >
</ body >
</ html >