带委托的Swift扩展(UIViewController)

class MailSender : NSObject , MFMailComposeViewControllerDelegate {
    var currentController : UIViewController!
    var recipient : [String]!
    var message : String!
    var compltion : ((String)->())?
    init(from Controller:UIViewController,recipint:[String],message:String) {
        currentController = Controller
        self.recipient = recipint
        self.message  = message
    }

    func sendMail() {
        if MFMailComposeViewController.canSendMail() {
            let mail = MFMailComposeViewController()
            mail.mailComposeDelegate = self
            mail.setToRecipients(recipient)
            mail.setMessageBody(message, isHTML: true)
            currentController.present(mail, animated: true)
        } else {
            if compltion != nil {
                compltion!("error")
            }
        }
    }

    func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
        if compltion != nil {
            compltion!("error")
        }
        controller.dismiss(animated: true)
    }
}

let mailsender = MailSender(from: self,recipint:["example@via.com"],message:"your message")
        mailsender.sendMail()
        mailsender.compltion = { [weak self] result in
            print(result)
            //other stuff

        }

记得我使用过简单的Clouser(completion),它以String作为参数来通知它是成功还是失败,但是您可以按照自己的命令来编写要求.in此外,还可以使用委托模式而不是clouser或callback。

。有关详细信息: https://medium.com/@JoyceMatos/dependency-injection-in-swift-87c748a167be

创建全局函数:

func sendEmail(address: String, body: String, subject: String, viewController: UIViewController) {
    //check if email is configured or throw error...
}