Activity controller adding subject to mail swift

In Swift, you can add a subject to an email using the Mail framework and an ActivityController. Here's an example:

import UIKit
import MessageUI

class ViewController: UIViewController, MFMailComposeViewControllerDelegate {

    let mailController = MFMailComposeViewController()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Set up the mail controller
        mailController.mailComposeDelegate = self
        mailController.setSubject("Your Subject")
        // Add recipients, body, etc.
    }

    func sendEmail() {
        // Present the mail controller
        present(mailController, animated: true, completion: nil)
    }

    // MARK: - MFMailComposeViewControllerDelegate

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

In this example, we create an instance of MFMailComposeViewController and set its mailComposeDelegate to self. We then set the subject of the email using the setSubject(_:) method.

To present the mail controller, we call the sendEmail() method, which presents the mail controller modally.

In the mailComposeController(_:didFinishWith:erro:) method, we dismiss the mail controller when the user finishes composing the email.

Note that you need to import the MessageUI framework and conform to the MFMailComposeViewControllerDelegate protocol to use the MFMailComposeViewController class.

Also, make sure to add the MessageUI framework to your target in your project settings.