如何以编程方式将附件添加到php中的默认邮件撰写表单？

$attachment = $_FILES['attachment'];

$targetDir = '/path/to/attachments/';
$targetFile = $targetDir . basename($attachment['name']);
move_uploaded_file($attachment['tmp_name'], $targetFile);

require 'path/to/PHPMailer/PHPMailerAutoload.php';

$mail = new PHPMailer;
$mail->isSMTP();
$mail->Host = 'smtp.example.com';
$mail->SMTPAuth = true;
$mail->Username = 'your-email@example.com';
$mail->Password = 'your-email-password';
$mail->SMTPSecure = 'tls';
$mail->Port = 587;

$mail->setFrom('your-email@example.com', 'Your Name');
$mail->addAddress($_POST['recipient']);
$mail->Subject = $_POST['subject'];
$mail->Body = $_POST['message'];

$mail->addAttachment($targetFile);

if ($mail->send()) {
    echo '邮件发送成功';
} else {
    echo '邮件发送失败：' . $mail->ErrorInfo;
}