discuz的image类使用

<input type="attach" name="file">//文件域的名字
//处理方法
//新图
			if(!empty($_FILES['attach']['tmp_name']) && is_uploaded_file($_FILES['attach']['tmp_name'])){
				$query = DB::query("select filename,filepath from pre_home_hall_pic where picid =$picid ");				
				while ($value = DB::fetch($query)) {
					$oldfilepath=$value['filepath'];
					$filename =$value['filename'];
				}
				$file_info = pathinfo($_FILES['attach']['name']);
				$ext = $file_info['extension'];// 取扩展名

				$filepath = dirname($oldfilepath).'/'.date('His').strtolower(random(16)).'.'.$ext;//随机重命名			
				$uploadpath = 'data/attachment/hall/'.$filepath;				
				if(!is_dir('data/attachment/hall/'.$oldfilepath)){
					unlink('data/attachment/hall/'.$oldfilepath);
					unlink('data/attachment/hall/'.$oldfilepath.'.thumb.jpg');				
				}
				$res = move_uploaded_file($_FILES['attach']['tmp_name'], $uploadpath);
				if($res){
					require_once libfile('class/image');
					$image = new image();
					$result = $image->Thumb($uploadpath, '', 140, 140, 1);						
				}
				$data['filename'] = $_FILES['attach']['name'];
				$data['filepath'] = $filepath;						
			}
			DB::update('home_hall_pic', $data, $wherearr);