暗藏iframe无刷新上传文件

class upload<br>{<br>   public $_file;<br><br>   public function __construct( $name =null)<br>   {<br>       if(is_null($name) || !isset($_FILES[$name]))<br>            $name = key($_FILES);<br>            <br>       if(!isset($_FILES[$name]))<br>           throw new Exception("并没有文件上传");<br>           <br>       $this->_file  = $_FILES[$name];<br>       <br>       if(!is_uploaded_file($this->_file['tmp_name']))<br>            throw new Exception("异常情况");<br>       if($this->_file['error'] !== 0)<br>            throw new Exception("错误代码:".$this->_file['error']);     <br>   }<br>   public function moveTo( $new_dir)<br>   {<br>       $real_dir = $this->checkDir($new_dir);<br>       return move_uploaded_file($this->_file['tmp_name'], $real_dir.'/'.$this->_file['name']);<br>   }<br>   private function checkDir($dir)<br>   {<br>       $real_dir = realpath($dir);<br>       if($real_dir === false)<br>           throw new Exception("给定目录{$dir}不存在");<br>       if(!is_writable($real_dir))<br>           throw new Exception("给定目录{$dir}不可写");<br>       return $real_dir;<br>   }

}