局部变量声明迅速

Question

I'm trying to allow for a user to send an email in my app but I get a:

Use of local variable 'configureMailComposeViewController' before its declaration

Here is the code.

func item(_ item: Int, selectedAtContactIndex index: Int) {
    var mailComposeViewController = configuredMailComposeViewController()
    if MFMailComposeViewController.canSendMail() {
        self.presentViewController(mailComposeViewController, animated: true, completion: nil)
    } else {

    }
}

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

    mailComposerVC.setToRecipients([EmailAddressArray[index]])
    mailComposerVC.setSubject("I need your help")

    return mailComposerVC
}

Answer 1

func configuredMailComposeViewController() -> MFMailComposeViewController

This right here is your function that has a return type MFMailComposeViewController which you will get when you will call this method.It will return you some result

Now the result from your above method func configuredMailComposeViewController() -> MFMailComposeViewControllercall need to be saved in a variable you just can not leave it to fly in the air .In order to save or get what ever this method does you need to do this -:

var mailComposeViewController = configuredMailComposeViewController()

So this makes it clear you need to call this mailComposeViewController = configuredMailComposeViewController() after your return function not before.

Exactly this-:

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

        mailComposerVC.setToRecipients([EmailAddressArray[index]])
        mailComposerVC.setSubject("I need your help")

        return mailComposerVC
    }





        func item(_ item: Int, selectedAtContactIndex index: Int) {

        if MFMailComposeViewController.canSendMail() {
var mailComposeViewController = configuredMailComposeViewController()
            self.presentViewController(mailComposeViewController, animated: true, completion: nil)
        } else {

        }
    }

Answer 2

Switch the order of the functions , put configuredMailComposeViewController function on top

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

    mailComposerVC.setToRecipients([EmailAddressArray[index]])
    mailComposerVC.setSubject("I need your help")

    return mailComposerVC
}





    func item(_ item: Int, selectedAtContactIndex index: Int) {
    var mailComposeViewController = configuredMailComposeViewController()
    if MFMailComposeViewController.canSendMail() {
        self.presentViewController(mailComposeViewController, animated: true, completion: nil)
    } else {

    }
}