都知道jquery都插件是非常强大的，最近分享点jquery插件效果，方便效果开发使用。
一、HTML代码
<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>jquery图片放大插件鼠标滑过图片放大效果</title>
<meta name="description" content="jquery图片放大插件制作一个当鼠标滑过图片，图片按等比例缩放放大效果。动画图片放大展示特效。jQuery插件。" />
</head>
<body>
<script type="text/javascript" src="js/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="js/jquery.zoomImgRollover.js"></script>
<script type="text/javascript">
$(document).ready(function() {
$("#testimg").zoomImgRollover();
});
</script>
<style type="text/css">
*{margin:0;padding:0;list-style-type:none;}
a,img{border:0;}
.demo{width:544px;margin:20px auto;}
</style>
<div class="demo">
<a href='http://www.3mooc.com/' style="border:1px solid #000;">
<img id="testimg" width="400" height="564" src="data:images/132ad.jpg" alt="" border="0">
</a>
</div>
</body>
</html>
二、插件代码（插件名称：jquery.zoomImgRollover.js）
(function(jQuery){
jQuery.fn.zoomImgRollover = function(options) {
var defaults = {
percent:30,
duration:600
};
var opts = jQuery.extend(defaults, options);
// static zoom function
function imageZoomStep(jZoomImage, x, origWidth, origHeight)
{
var width = Math.round(origWidth * (.5 + ((x * opts.percent) / 200))) * 2;
var height = Math.round(origHeight * (.5 + ((x * opts.percent) / 200))) * 2;
var left = (width - origWidth) / 2;
var top = (height - origHeight) / 2;
jZoomImage.css({width:width, height:height, top:-top, left:-left});
}
return this.each(function()
{
var jZoomImage = jQuery(this);
var origWidth = jZoomImage.width();
var origHeight = jZoomImage.height();
// add css ness. to allow zoom
jZoomImage.css({position: "relative"});
jZoomImage.parent().css({overflow: "hidden", display:"block", position: "relative", width: origWidth, height: origHeight});
jZoomImage.mouseover(function()
{
jZoomImage.stop().animate({dummy:1},{duration:opts.duration, step:function(x)
{
imageZoomStep(jZoomImage, x, origWidth, origHeight)
}});
});
jZoomImage.mouseout(function()
{
jZoomImage.stop().animate({dummy:0},{duration:opts.duration, step:function(x)
{
imageZoomStep(jZoomImage, x, origWidth, origHeight)
}});
});
});
};
})(jQuery);