Can't get app to dismiss the mail compose view controller & return to first screen

Question

I'm using the Swift book to try to learn to code. I added the delegate method to dismiss the view, but it's not working. What am I missing here?

@IBAction func emailButtonTapped(_ sender: UIButton) {

    if !MFMailComposeViewController.canSendMail() {
        print("Can not send mail")
        return
    }

    guard MFMailComposeViewController.canSendMail() else { return }

    let mailComposer = MFMailComposeViewController()
    mailComposer.mailComposeDelegate = self

    mailComposer.setToRecipients(["[email protected]"])
    mailComposer.setSubject("Look at this")
    mailComposer.setMessageBody("Hello, this is an email from the app I made.", isHTML: false)

    present(mailComposer, animated: true, completion: nil)

    func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
        dismiss(animated: true, completion: nil)
    }

}

Answer 1

You just need to declare the delegate function outside of the IBAction:

@IBAction func emailButtonTapped(_ sender: UIButton) {
    if !MFMailComposeViewController.canSendMail() {
        print("Can not send mail")
        return
    }

    guard MFMailComposeViewController.canSendMail() else { return }

    let mailComposer = MFMailComposeViewController()
    mailComposer.mailComposeDelegate = self

    mailComposer.setToRecipients(["[email protected]"])
    mailComposer.setSubject("Look at this")
    mailComposer.setMessageBody("Hello, this is an email from the app I made.", isHTML: false)

    present(mailComposer, animated: true, completion: nil)
}

func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
    dismiss(animated: true, completion: nil)
}