<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>test</title>
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
</head>
<style>
.btn{
display: block;
background:green;
color:#fff;
text-decoration:none;
padding:5px;
float: left;
margin:0 5px;
}
</style>
<body>
<label for="up">
<input type="file" id="up" style="display:none;">
<span class="btn">选择图片</span>
</label>
<a href="javascript:;" class="btn">上传</a>
<img src="" id="pic">
</body>
</html>
<script>
function $( id ){
return document.getElementById(id);
}
//改变的时候才获取内容
$(‘up‘).onchange = function(){
if ( this.files != undefined ) {
var url = window.webkitURL.createObjectURL( this.files[0] );
$(‘pic‘).src = url;
}
}
</script>
原文：http://www.cnblogs.com/zion0707/p/4475403.html