I have a parent view controller and a child view controller that takes up a portion of the parent's main view:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let childVC = ChildVC()
addChild(childVC)
childVC.view.frame = CGRect(origin: CGPoint(x: 100, y: 100), size: CGSize(width: 200, height: 200))
view.addSubview(childVC.view)
childVC.didMove(toParent: self)
}
}
class ChildVC: UIViewController {
override func loadView() {
let v = UIView()
v.backgroundColor = .cyan
view = v
}
override func viewDidLoad() {
super.viewDidLoad()
let button = UIButton(type: .system)
button.setTitle("Present", for: .normal)
button.addTarget(self, action: #selector(pressed), for: .touchUpInside)
button.sizeToFit()
view.addSubview(button)
}
@objc func pressed() {
self.definesPresentationContext = true
self.providesPresentationContextTransitionStyle = true
self.modalTransitionStyle = .crossDissolve
let pvc = PresentedVC()
pvc.modalPresentationStyle = .currentContext
self.present(pvc, animated: true, completion: nil)
}
}
class PresentedVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .yellow
let button = UIButton(type: .system)
button.setTitle("Dismiss", for: .normal)
button.addTarget(self, action: #selector(pressed), for: .touchUpInside)
button.sizeToFit()
view.addSubview(button)
}
@objc func pressed() {
self.dismiss(animated: true, completion: nil)
}
}
When I present a view controller using the currentContext
style, it presents the new view controller as it should, covering only the child view controller's view:
However, when I dismiss it, the size of the ChildVC
's main view takes up the entire screen:
When I log the superview of the ChildVC
's main view, it's still a subview of the parent view controller's main view so I'm not sure why this is happening.
Just change your presentationStyle
to .overCurrentContext
like this:
@objc func pressed() {
self.definesPresentationContext = true
self.providesPresentationContextTransitionStyle = true
self.modalTransitionStyle = .crossDissolve
let pvc = PresentedVC()
pvc.modalPresentationStyle = .overCurrentContext // <-- here
pvc.modalTransitionStyle = .crossDissolve // <-- and here
self.present(pvc, animated: true, completion: nil)
}
It will prevent the unwanted upscaling.