ios - MFMailComposeViewController didFinishWith结果中的Swift显示警报

我想在用户取消电子邮件时显示警报。为此，我使用以下代码：

func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {

    if result == .cancelled {

        let alertController = UIAlertController(title: "E-Mail not sent!", message: "E-Mail not sent.", preferredStyle: .alert)

        alertController.addAction(UIAlertAction(title: "OK", style: .cancel, handler: { (action: UIAlertAction!) in
        }))

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

    controller.dismiss(animated: true, completion: nil)
}

将调用该函数并关闭邮件视图，但不显示警报。我在UITableViewController中使用此代码。有人能帮我吗？

最佳答案

在完成块中显示alertController。

controller.dismiss(animated: true, completion: {
if result == .cancelled {
        let alertController = UIAlertController(title: "E-Mail not sent!", message: "E-Mail not sent.", preferredStyle: .alert)

        alertController.addAction(UIAlertAction(title: "OK", style: .cancel, handler: { (action: UIAlertAction!) in
        }))

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

这样地。。

关于ios - MFMailComposeViewController didFinishWith结果中的Swift显示警报，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42040013/