用codeigniter中生成的pdf发送邮件

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Pdf_email extends CI_Controller {

    public function __construct() {
        parent::__construct();
        $this->load->library('email');
    }

    public function index() {
        // 生成PDF文件
        $this->load->library('pdf');

        // 设置PDF参数和内容
        $pdf = new Pdf();
        $pdf->AddPage();
        $pdf->SetFont('Arial', 'B', 16);
        $pdf->Cell(40, 10, 'Hello World!');

        // 保存PDF文件
        $pdfFilePath = 'path/to/save/pdf.pdf';
        $pdf->Output($pdfFilePath, 'F');

        // 发送邮件
        $this->email->from('your@example.com', 'Your Name');
        $this->email->to('recipient@example.com');
        $this->email->subject('PDF Email');
        $this->email->message('Please find the attached PDF file.');

        // 添加PDF文件作为附件
        $this->email->attach($pdfFilePath);

        // 发送邮件
        $this->email->send();

        // 删除生成的PDF文件
        unlink($pdfFilePath);

        echo 'Email sent with PDF attachment.';
    }
}