扩展类CI_controller PHPExcel给出格式错误或无效的扩展错误

Question

我正在尝试使用CodeIgniter导出Excel，填充代码给我输出错误它几天前工作正常但是现在它给了我错误

<?php
class reports extends CI_controller {

    public function __construct() {
        parent::__construct();
        $user = $this->Auth->get_user_id();
        if (!$user) {
            header("Location:" . base_url() . "index.php");
            exit();
        }
    }


 public function test(){
date_default_timezone_set('Europe/London');
if (PHP_SAPI == 'cli')
    die('This example should only be run from a Web Browser');
/** Include PHPExcel */
require_once 'application/controllers/Classes/PHPExcel.php';
// Create new PHPExcel object
$objPHPExcel = new PHPExcel();
// Set document properties
$objPHPExcel->getProperties()->setCreator("Maarten Balliauw")
                             ->setLastModifiedBy("Maarten Balliauw")
                             ->setTitle("Office 2007 XLSX Test Document")
                             ->setSubject("Office 2007 XLSX Test Document")
                             ->setDescription("Test document for Office 2007 XLSX, generated using PHP classes.")
                             ->setKeywords("office 2007 openxml php")
                             ->setCategory("Test result file");
// Add some data
$objPHPExcel->setActiveSheetIndex(0)
            ->setCellValue('A1', 'Hello')
            ->setCellValue('B2', 'world!')
            ->setCellValue('C1', 'Hello')
            ->setCellValue('D2', 'world!');
// Miscellaneous glyphs, UTF-8
$objPHPExcel->setActiveSheetIndex(0)
            ->setCellValue('A4', 'Miscellaneous glyphs')
            ->setCellValue('A5', 'éàèùâêîôûëïüÿäöüç');
// Rename worksheet
$objPHPExcel->getActiveSheet()->setTitle('Simple');
// Set active sheet index to the first sheet, so Excel opens this as the first sheet
$objPHPExcel->setActiveSheetIndex(0);
// Redirect output to a client’s web browser (Excel5)
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename="01simple.xls"');
header('Cache-Control: max-age=0');
// If you're serving to IE 9, then the following may be needed
header('Cache-Control: max-age=1');
// If you're serving to IE over SSL, then the following may be needed
header ('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); // Date in the past
header ('Last-Modified: '.gmdate('D, d M Y H:i:s').' GMT'); // always modified
header ('Cache-Control: cache, must-revalidate'); // HTTP/1.1
header ('Pragma: public'); // HTTP/1.0
ob_clean();
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
$objWriter->save('php://output');
exit;
    }

}
?>

上面的代码给出了如下图所示的输出 output for above code

但如果我删除类报告扩展CI_controller并运行代码作为函数它工作正常并生成完美的Excel输出

我在CI_controller文件中的代码

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package     CodeIgniter
 * @author      ExpressionEngine Dev Team
 * @copyright   Copyright (c) 2008 - 2014, EllisLab, Inc.
 * @license     http://codeigniter.com/user_guide/license.html
 * @link        http://codeigniter.com
 * @since       Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * CodeIgniter Application Controller Class
 *
 * This class object is the super class that every library in
 * CodeIgniter will be assigned to.
 *
 * @package     CodeIgniter
 * @subpackage  Libraries
 * @category    Libraries
 * @author      ExpressionEngine Dev Team
 * @link        http://codeigniter.com/user_guide/general/controllers.html
 */
class CI_Controller {

    private static $instance;

    /**
     * Constructor
     */
    public function __construct()
    {
        self::$instance =& $this;

        // Assign all the class objects that were instantiated by the
        // bootstrap file (CodeIgniter.php) to local class variables
        // so that CI can run as one big super object.
        foreach (is_loaded() as $var => $class)
        {
            $this->$var =& load_class($class);
        }

        $this->load =& load_class('Loader', 'core');

        $this->load->initialize();

        log_message('debug', "Controller Class Initialized");
    }

    public static function &get_instance()
    {
        return self::$instance;
    }
}
// END Controller class

/* End of file Controller.php */
/* Location: ./system/core/Controller.php */
?>