效果如下：
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>鼠標懸停邊框運動效果</title>
<script src="js/jquery-1.8.3.min.js"></script>
<style>
* {
margin:0;
padding:0;
list-style:none;
}
img {
border:0;
width:300px;
height:150px;
}
.box {
width:300px;
height:150px;
margin:20px auto;
position:relative;
border:1px solid #eee;
}
.box .border-left {
width:1px;
height:0px;
background:red;
position:absolute;
left:-1px;
bottom:0;
}
.box .border-bottom {
width:0px;
height:1px;
background:red;
position:absolute;
left:0;
bottom:0px;
}
.box .border-top {
width:0px;
height:1px;
background:red;
position:absolute;
right:0;
top:0px;
}
.box .border-right {
width:1px;
height:0px;
background:red;
position:absolute;
right:-1px;
top:0;
}
</style>
</head>
<body>
<div class="box">
<img src="img/3.jpg">
<div class="border-left"></div>
<div class="border-bottom"></div>
<div class="border-top"></div>
<div class="border-right"></div>
</div>
<div class="box">
<img src="img/3.jpg">
<div class="border-left"></div>
<div class="border-bottom"></div>
<div class="border-top"></div>
<div class="border-right"></div>
</div>
<script>
$(function() {
var lanren_width = $('.box').width();
var lanren_height = $('.box').height();
$('.box').each(function() {
$(this).hover(function() {
$(this).find('.border-left,.border-right').stop().animate({
height: lanren_height + 'px'
}, 400);
$(this).find('.border-top,.border-bottom').stop().animate({
width: lanren_width + 'px'
}, 400);
}, function() {
$(this).find('.border-left,.border-right').stop().animate({
height: '0'
}, 400);
$(this).find('.border-top,.border-bottom').stop().animate({
width: '0'
}, 400);
});
});
});
</script>
</body>
</html>