如何在PHP中发送一封以pdf格式作为附件的电子邮件？

require 'path/to/PHPMailer/src/PHPMailer.php';
require 'path/to/PHPMailer/src/SMTP.php';
require 'path/to/PHPMailer/src/Exception.php';

$mail = new PHPMailer\PHPMailer\PHPMailer();

$mail->isSMTP();
$mail->Host = 'smtp.example.com';  // 替换为你的SMTP服务器地址
$mail->SMTPAuth = true;
$mail->Username = 'your-email@example.com';  // 替换为你的邮箱地址
$mail->Password = 'your-email-password';  // 替换为你的邮箱密码
$mail->SMTPSecure = 'tls';
$mail->Port = 587;

$mail->setFrom('your-email@example.com', 'Your Name');  // 替换为你的邮箱地址和姓名
$mail->addAddress('recipient@example.com', 'Recipient Name');  // 替换为收件人的邮箱地址和姓名

$mail->addAttachment('path/to/attachment.pdf');  // 替换为PDF附件的路径

$mail->Subject = 'Email with PDF attachment';
$mail->Body = 'Please find the attached PDF.';

if ($mail->send()) {
    echo 'Email sent successfully.';
} else {
    echo 'Error sending email: ' . $mail->ErrorInfo;
}