最近碰到input type=file 之前用模拟点击来实现美化，发现在IE7下会有bug导致图片上传不上去，最后改用直接美化的方法
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
/*a upload */
.a-upload {
padding: 4px 10px;
height: 20px;
line-height: 20px;
position: relative;
cursor: pointer;
color: #888;
background: #fafafa;
border: 1px solid #ddd;
border-radius: 4px;
overflow: hidden;
display: inline-block;
*display: inline;
*zoom: 1
} .a-upload input {
position: absolute;
font-size: 100px;
right: 0;
top: 0;
opacity: 0;
filter: alpha(opacity=0);
cursor: pointer
} .a-upload:hover {
color: #444;
background: #eee;
border-color: #ccc;
text-decoration: none
} .file {
position: relative;
display: inline-block;
background: #D0EEFF;
border: 1px solid #99D3F5;
border-radius: 4px;
padding: 4px 12px;
overflow: hidden;
color: #1E88C7;
text-decoration: none;
text-indent: 0;
line-height: 20px;
}
.file input {
position: absolute;
font-size: 100px;
right: 0;
top: 0;
opacity: 0;
}
.file:hover {
background: #AADFFD;
border-color: #78C3F3;
color: #004974;
text-decoration: none;
}
</style>
</head>
<body>
<a href="javascript:;" class="a-upload">
<input type="file" name="" id="">点击这里上传文件
</a> <a href="javascript:;" class="file">选择文件
<input type="file" name="" id="">
</a>
</body>
</html>
非原创，网络收集得到。