首先ajax不能上传文件，这误导了我有段时间，今晚睡不着就照着说明做了个无刷新上传文件
其实原理很简单
<form enctype="multipart/form-data" method="POST" target="upload" action="http://localhost/class.upload.php" ><br /> <input type="file" name="uploadfile" /><br /> <input type="submit" /> <br /></form><br /><iframe name="upload"></span>
<pre class="code">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 /> }}
调用示例：
$inputName = 'uploadfile'; <br /> // 即<input type=“file" name="uploadfile" /> 中的name值，不填也行<br />$upload = new upload($inputName);<br />$new_dir = "/www"; // 将文件移动到的路径<br />$upload->moveTo($new_dir);
