ios - 单击发送按钮之前的联系人按钮时出现黑屏

Question

只是试图让用户发送电子邮件。单击“联系人”按钮时，我进入黑屏而不是显示 mailComposer。

调试器响应

2018-05-14 11:10:59.465952-0400 App[2333:757177] 无法在 (UIButton) 上设置 (keyPath) 用户定义的检查属性:[ setValue:forUndefinedKey:]: 此类不是键值编码- 符合 key keyPath。

但是，只有在使用 SWReveal 函数从左向右滑动菜单时才会发生这种情况。从下面删除代码时，所有其他功能都可以正常工作。只有在使用下面的代码时，才会在按下“按钮接触”时出现黑屏。

import Foundation
import UIKit
import MessageUI

class SendEmailVC: MFMailComposeViewController, MFMailComposeViewControllerDelegate
{
@IBAction func Send_Tapped(_ sender: Any)
{

    if MFMailComposeViewController.canSendMail()
    {
        contact()
        let mailComposeViewController = configureMailController() //FIXED √
        self.present(mailComposeViewController, animated: true, completion: nil)
    }
    else
    {
        showMailError()
    }
}

func configureMailController() -> MFMailComposeViewController
{
    let mailComposerVC = MFMailComposeViewController()
    mailComposerVC.mailComposeDelegate = self

    mailComposerVC.setToRecipients(["testing@gmail.com"])
    mailComposerVC.setSubject("Hello")
    mailComposerVC.setMessageBody("How are you doing?", isHTML: false)

    return mailComposerVC
}


/*
 * DON'T EDIT THE CODE BELOW.
 */


func showMailError()
{
    let sendMailErrorAlert = UIAlertController(title: "Email failed to send", message: "Your device fail to send the email", preferredStyle: .alert)

    let dismiss = UIAlertAction(title: "Dale", style: .default, handler: nil)
    sendMailErrorAlert.addAction(dismiss)
    self.present(sendMailErrorAlert, animated: true, completion: nil)
}

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

Answer 1

请使用代码在 swift 中打开带有如下扩展名的邮件。

extension SendEmailVC: MFMailComposeViewControllerDelegate {

func contact() {

    if !MFMailComposeViewController.canSendMail() {
        ROAlert.warningAlertUnderNavigation(ROConstants.More.kNoMailConfigured, onView: self.view)
        return ()
    }
    let composeVC = MFMailComposeViewController()
    composeVC.mailComposeDelegate = self
    composeVC.setToRecipients([ROConstants.More.kContactEmail])
    // Present the view controller modally.
    self.present(composeVC, animated: true, completion: nil)
}

//MARK: - MFMailComposeViewControllerDelegate

func mailComposeController(_ controller: MFMailComposeViewController,
    didFinishWith result: MFMailComposeResult, error: Error?) {
    // Check the result or perform other tasks.

    // Dismiss the mail compose view controller.
    controller.dismiss(animated: true, completion: nil)
}