如果安装了 Mail 则执行功能，如果没有则打开应用商店页面

Question

我正在尝试按照标题所说的操作，但是当我点击按钮打开邮件时，我的应用程序崩溃了，而我没有安装邮件应用程序。你能帮我解决这个问题吗？

代码：

if UIApplication.shared.canOpenURL(URL(string: "mailto://")!) {
            // Mail is installed. Launch Mail and start function:
            let toRecipients = ["oExample@gmail.com"]

        let mc: MFMailComposeViewController = MFMailComposeViewController()

        mc.mailComposeDelegate = self

        mc.setToRecipients(toRecipients)
        mc.setSubject("Why does it crash?")

        mc.setMessageBody("שם הבר: \(CrashNameField.text!) \n\nעיר: \(CrashReasonNameField.text!)", isHTML: false)

        self.present(mc, animated: true, completion: nil)

    }else {
            // Mail is not installed. Launch AppStore to install Mail app
            UIApplication.shared.openURL(URL(string: "https://itunes.apple.com/gb/app/mail/id1108187098?mt=8")!)
        }
    }

崩溃收集日志：

libc++abi.dylib: terminating with uncaught exception of type NSException 在线崩溃：class AppDelegate: UIResponder, UIApplicationDelegate{。额外信息：Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present a nil modal view controller on target

Answer 1

试试这个方法

 var picker = MFMailComposeViewController()
    if MFMailComposeViewController.canSendMail() {
        picker.mailComposeDelegate = self
        picker.setSubject("Test mail")
        picker.setMessageBody(messageBody.text, isHTML: true)
        present(picker as? UIViewController ?? UIViewController(), animated: true) { _ in }
    }

original post here

如果安装了 Mail 则执行功能，如果没有则打开应用商店页面

If Mail is installed Do function , if not Open app store page

ios

swift

email

url

url-scheme

代码：

崩溃收集日志：