原文： http://my.oschina.net/rst/blog/638135
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
<title>preview image</title>
</head>
<body>
<form>
<input type="file">
</form>
<script src="/static/js/jquery.min.js"></script>
<script>
$('input[type="file"]').change(function(e){
reader = new FileReader();
reader.readAsDataURL(e.target.files[0]);
reader.onload = function(){
$('body').append($('<img />', {src: reader.result}));
};
});
</script>
</body>
</html>