What the equivalent of activity life cycle in iOS?

Question

Actually, I would say that both iOS ViewControllers and Android Activities have their lifecycle methods. For example an equivalent of ViewController.viewDidLoad() is Activity.onCreate() ?

Else I still need to know the equivalent of the other :

• OnStart()
• OnRestart()
• OnResume()
• OnStop()
• OnDestroy()
• OnPause()

Answer 1

This is a comparison between the lifecycle of Android vs iOS:

• Note: viewDidUnload is deprecated after iOS 6

Answer 2

Here's how to get it done the Droid way:

import Foundation
import SwiftUI
import UIKit

public class AppleActivity : UIViewController {
    
  
    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
        initialize()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        initialize()
    }
    
    override public func viewDidLoad() -> Void {
        super.viewDidLoad()
        onCreate()
    }
    
    override public func viewWillAppear(_ animated: Bool) -> Void {
        super.viewWillAppear(animated)
        onStart()
    }

    
    public func initialize(){
        NotificationCenter.default.addObserver(self, selector: #selector(onStart), name: UIApplication.willEnterForegroundNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(onResume), name: UIApplication.didBecomeActiveNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(onPause), name: UIApplication.willResignActiveNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(onStop), name: UIApplication.didEnterBackgroundNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(onDestroy), name: UIApplication.willTerminateNotification, object: nil)
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }
    
    
    public func onCreate() {
        print("onCreate()")
    }
    
    @objc public func onStart() {
        print("onStart()")
    }
    
    @objc public func onResume() {
        print("onResume()")       
    }
    
    @objc public func onPause() {
        print("onPause()")        
    }
    
    @objc public func onStop() {
        print("onStop()")         
    }
    
    @objc public func onDestroy() {
        print("onDestroy()")       
    }
    
    
}


struct AppleActivityStruct : UIViewControllerRepresentable {
    
    typealias UIViewControllerType = AppleActivity
    
    public func makeUIViewController(context : Context) -> AppleActivity {
        return AppleActivity()
    }
    
    public func updateUIViewController(_ uiViewController : AppleActivity, context : Context) {
            // Update the view controller here if needed
    }
}

Now you get all your callbacks triggered everytime you want it, no stress + no wahala

N.B
Since onStart() via NotificationCenter.default.addObserver(self, selector: #selector(onStart), name: UIApplication.willEnterForegroundNotification, object: nil) might not get invoked the first time the scene of the UIViewController is created, that's why a call to it is present within viewWillAppear(_ animated: Bool)