感谢@jmadsen

这可以通过正确的加载顺序来实现:

This is possible by just getting the order of loading correct:

/*
 * --------------------------------------------------------------------
 * LOAD THE BOOTSTRAP FILE
 * --------------------------------------------------------------------
 *
 * And away we go...
 *
 */
// Composer Autoloader
require FCPATH . 'vendor/autoload.php';

require_once BASEPATH.'core/CodeIgniter.php';

/* End of file index.php */