Call function from other ViewController

Question

I have two ViewControllers, FirstViewController and SecondViewController. Both have an own Swift file, FirstViewController.swift and

Answer 1

You may use NSNotificationCentre to accomplish this task.

In viewDidLoad method of your SecondViewController class register self as observer to receive notification broadcasts:-

override func viewDidLoad() {
    NotificationCenter.default.addObserver(self, selector: #selector(showAlert), name: NSNotification.Name(rawValue: "callForAlert"), object: nil)
}

and in FirstViewController's button action method you should fire the notification by writing :-

@IBAction func callFunctionInOtherClass(sender: AnyObject) {
    //Call "func showAlert" in SecondViewController when clicking the UIButton in FirstViewController
    NotificationCenter.default.post(name: NSNotification.Name(rawValue: "callForAlert"), object: nil)
}

Don't forget to call removeObserver in SecondViewController's viewDidUnload method.