I know there are a lot of answers out there about similar issues, but it seems all of them are don't fit to my problem. And I am new to Swift and my head is burning about all this stuff.

The task is very simple. I have a ViewController and a Class called "TimeIsTicking", which I defined in a separate Swift File. I did this, because I want to feed 5 ViewController (which are nested in TabBarController) with data from the Timer and they all have to run "synchronized".

The function fireTimer puts every second the value of 1 to the variable seconds.

In the ViewController is a Label and I want the Label to be updated every time when the timer puts a new value to seconds.

dayLabelText gets the data, here is everything fine, but from that point I'm stuck. Label Text isn't been updated.

I suspect, that there has to be a "loop" to reload the data for the Label and I thought the loop in fireTimer would be enough but I was obviously wrong.

I tried the "Observer Thing" and the "Dispatchqueue Thing" but I didn't play well ((obviously).

Help would be much appreciated.

Here is the code of the timer class:

import Foundation
import UIKit

class TimeIsTicking {
    
    var seconds: Int = 0
    
    static let timeFlow = TimeIsTicking()

    func fireTimer() {
        let finance = FinanceVC()
        Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { timer in
            self.seconds  = 1
            finance.dayLabelText = "\(self.seconds)"
            print("Seconds: ", self.seconds)
            print("LabelText: ", finance.dayLabelText)   
        }
    }  
}

And here is the code of the VieWController:

import UIKit

class FinanceVC: UIViewController {
    
    @IBOutlet weak var dayLabel: UILabel!
    
    var dayLabelText = String(TimeIsTicking.timeFlow.seconds)
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        dayLabel.text = dayLabelText

        TimeIsTicking.timeFlow.fireTimer()
  
        }
        // Do any additional setup after loading the view.

}

CodePudding user response：

I see a few issues:

• The finance object goes out of scope when fireTimer() returns. It will be deallocated then. The timer will be setting a label text on a no longer existing view controller.
• Instantiating a UIViewController with FinanceVC() doesn't display it on screen. After instantiating you need to explicitly show. You can do this for example by calling present(_:animated:completion:) from a parent view controller.
• The timer updates dayLabelText which does not update dayLabel.text

Might be good to follow a basic YT tutorial on how to display a view controller.

Good luck, you'll get it soon enough!