文件上传拖拽效果，以及图片，MP3，MP4格式的预览，ajax上传
1.创建upload.html,最后引入zphupload.js(注意放在最后)
<meta charset="utf-8">
<div id="drop_area" >将图片拖拽到此</div>
<button onclick="zphxhrupload('upload.php')">ajax上传</button>
<script src="zphupload.js"></script>2.创建upload.php
<?php
print_r($_FILES["file"]);
$name = $_FILES["file"]["name"]; //中文可能乱码使用iconv函数
move_uploaded_file($_FILES["file"]["tmp_name"],iconv("UTF-8","gb2312",$name));
?>