Question

有人可以帮助我解决这个问题。我可以毫无问题地发送电子邮件，但是如果我尝试返回到以前的视图，则在单击“发送”或“取消”时会卡住。

我尝试在此处查看一些解决方案，但是它们没有解决问题

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

    }



@IBAction func sendMailPressed(_ sender: Any){
    if MFMailComposeViewController.canSendMail(){
        let mailVC = MFMailComposeViewController()

        mailVC.delegate = self
        mailVC.setToRecipients(["xxx@mail.com"])
        mailVC.setSubject("image to you!!")
        mailVC.setMessageBody("hello", isHTML: false)

        let image = imageView.image?.ResizeImage(newWidth: 200)
        if let imageD = image?.pngData(){

        let imageData = imageD  as NSData

            mailVC.addAttachmentData(imageData as Data, mimeType: "image/png", fileName: "i.png")

        }
        self.present(mailVC, animated: true, completion: nil)

    }
}

Answer 1

更改

Int

到

f = Term (CVar 2)
g = Term CInt

-- By matching against Left and Right, we're letting GHC know that unify
-- should return an Either; this disambiguates `m`
main = case unify [(f, g)] of
  Left _      -> print "did not unify"
  Right subst -> doMoreWork subst

-- The Int here disambiguates `v`
doMoreWork :: Subst CTypeF Int -> IO ()
doMoreWork subst = undefined -- fill in the blank!

其他一切都会自然而然地跟随。此视图控制器还需要成为 MFMailComposeViewControllerDelegate。

MFMailComposeViewController-无法取消或返回上一个视图

1 个答案: