问在Codeigniter中使用URL发送带有附件的电子邮件

EN

    public function SendInvoice(){
        $orderid = $this->uri->segment(3);
        $result = $this->order->GetCustOrder($orderid);

        unset($data);
        $data = array(
                        $OrderID,
                        $result[0]->cust_id,
                        $result[0]->cust_name,
                        $result[0]->cust_email
                      );
        $this->store_email->SendInvoiceToCust($data); //library

        $this->session->set_flashdata('sent_email','Email has been sent to customer.');
        redirect('Store/Index');
    }   

    public function SendInvoiceToCust($data){
        $message = "Dear Valued Customer, <br><br>Thank you for Purchased at Store. <br/><br/>Kindly refer the attachment to view your Invoice.";
        //$attached_file = base_url(). 'index.php/Store/GI/' .$data[0]. '.pdf';
        $form = base_url(). 'index.php/Store/GI/' .$data[0]. '.pdf';
        $attachment = chunk_split(base64_encode($form));

        $separator = md5(time());

        $message .= "--" . $separator . PHP_EOL;
        $message .= "Content-Type: application/octet-stream; name=\"\" . $data[0]. '.pdf'\"" . PHP_EOL;
        $message .= "Content-Transfer-Encoding: base64" . PHP_EOL;
        $message .= "Content-Disposition: attachment" . PHP_EOL . PHP_EOL;
        $message .= $attachment . PHP_EOL . PHP_EOL;
        $message .= "--" . $separator . "--";           

        $this->email->from('email@gmail.com', 'Store');
        $this->email->to('email2@gmail.com'); 

        $this->email->subject('Store INVOICE [Do not reply]');
        $this->email->message($message);
        $this->email->attach($attachment);
        $this->email->send();


    }