Swift 4 Call ViewWillAppear after dismissing View Controller

Question

I would like to call viewWillAppear after dismissing a layover ViewController.

ViewController1 -> Segue -> ViewController2

In VeiwController2

1.)

self.dismiss(animated: true, completion: nil)

2.)

 override func viewDidDisappear(_ animated: Bool) {

       ViewController1().viewWillAppear(true)

    }

In VeiwController1

When viewWillAppear is called im getting null errors crashing my app. How can i dismiss a overContext ViewController and call the viewWillAppear method in a correct manner.

Solution 1

viewWillAppear is called automatically when you dismiss VC2. Delete: ViewController1().viewWillAppear(true)

Try deleting:

super.viewWillAppear(animated) in VC1. viewDidAppear not getting called

Does it even go back to your VC? self.dismiss works with "Present Modally" segue here. Or embed in NavigationBar, with popViewController

Solution 2

// Override this function in ViewController1
override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(true)

 //Your code here will execute after viewDidLoad() or when you dismiss the child viewController  

}

I'd suggest you go through the life cycle of ViewController. Apple documentation for ViewController life cycle

Comments

[husharoonie]

still not calling it

[husharoonie]

it still doesnt call viewWillAppear when i dismiss

[Kowboj]

Does it even go back to your VC? self.dismiss works with "Present Modally" segue here (change the segue). Or embed in NavigationBar, with popViewController. Then view will appear.

[Tushar Katyal]

Could you share the project link ?

[LateNate]

Can you elaborate on 'the problem was the Segue' @husharoonie? I have a similar problem. Can't figure out the answer.

[Kowboj]

@LateNate if you push to another controller you can go back by typing 'navigationController?.popViewController(animated: true)'. Self.dismiss doesn't work. Self.dismiss works with modal presentation style 'present(secondController, animated: true)'

[LateNate]

Thanks @Kowboj. I found a less than ideal solution to this myself using NSNotificationCenter. Rather than using ViewWillAppear to update after dismissing I used a notification observer. Didn't want to do it that way, but it works.