UIView is not updating when popToViewController on NavigationController - ios

Question

I have a navigationController where I pushViewController two viewcontrollers, OneViewController and TwoViewController. When I rotating the device on the pushed TwoViewController, and then popToViewController (see code) back to OneViewController the view on OneViewController is not updated / rotated.
Update: I have created a small sample project, where I have added a navigationController and two ViewControllers - and then doing the same thing. That is actually working, the only different I can think of is that the Views in my application that fails, is that I load the views from Xib files.
All the constraints in the view is setup in Interface Builder - and saved to the xib file.
I have the following in the view that I reference in Interface Builder as the ViewControllers view:
func loadViewFromNib() -> UIView? {
let bundle = Bundle(for: type(of: self))
let nib = UINib(nibName: String(describing: type(of: self)), bundle: bundle)
return nib.instantiate(
withOwner: self,
options: nil).first as? UIView
}
override public func awakeFromNib() {
super.awakeFromNib()
// Not setting up any constraints in code of setting any frame here.
}
If I then rotate on the OneViewController it then renders fine.
Do you know why it is not updating when using popToViewController?
let viewControllers: [UIViewController] = self.navigationController!.viewControllers
for aViewController in viewControllers {
if aViewController is OneViewController {
aViewController.view.updateConstraints()
aViewController.view.setNeedsDisplay()
aViewController.view.layoutIfNeeded()
aViewController.view.setNeedsLayout()
self.navigationController!.popToViewController(aViewController, animated: true)
break
}
}
On the view I have also tried this:
override func viewWillShow(passingInAnyObject: AnyObject?) {
self.updateConstraints()
self.setNeedsDisplay()
self.layoutIfNeeded()
self.setNeedsLayout()
}

Answer 1

Call the functionality which you want to update on the viewcontroller to which you pop in viewWillAppear method:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
}

Answer 2

Super strange, but the following solved the problem:
Setting: aViewController.view.frame.size = UIScreen.main.bounds.size
Change the following:
let viewControllers: [UIViewController] = self.navigationController!.viewControllers
for aViewController in viewControllers {
if aViewController is OneViewController {
aViewController.view.updateConstraints()
aViewController.view.setNeedsDisplay()
aViewController.view.layoutIfNeeded()
aViewController.view.setNeedsLayout()
self.navigationController!.popToViewController(aViewController, animated: true)
break
}
}
TO:
let viewControllers: [UIViewController] = self.navigationController!.viewControllers
for aViewController in viewControllers {
if aViewController is OneViewController {
aViewController.view.frame.size = UIScreen.main.bounds.size
self.navigationController!.popToViewController(aViewController, animated: true)
break
}
}