how to lock portrait orientation for only main view using swift

Question

I have created an application for iPhone, using swift, that is composed from many views embedded in a navigation controller. I would like to lock the main v

Answer 1

This requires two things

• Informing the controller of its support for rotation.
• Enforcing rotation and then handing over responsibility to a controller that knows its support for rotation.

Declare an extension on view controller that forces orientation to portrait.

extension UIViewController {

  func forcePortrait() {
    UIView.setAnimationsEnabled(false)
    UIDevice.current.setValue(UIInterfaceOrientation.portrait.rawValue, forKey: "orientation")
    UIView.setAnimationsEnabled(true)
  }

}

Any view controller that is locked to portrait could inherit traits.

class PortraitViewController: UIViewController {

  override open var supportedInterfaceOrientations: UIInterfaceOrientationMask { return .portrait }
  override open var shouldAutorotate: Bool { return false }

  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    forcePortrait()
  }

}

Any view controller that is capable of rotating between portrait and landscape can inherit those traits.

class LandscapeViewController: UIViewController {

  override open var supportedInterfaceOrientations: UIInterfaceOrientationMask { return [.landscape, .portrait]  }
  override open var shouldAutorotate: Bool { return true }

  override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    // if leaving for a portrait only screen, force portrait.
    // forcePortrait()
  }

}

If your landscape view controller is about to segue to a portrait locked screen. Be sure to lock the orientation just before leaving. Then rely on the portrait view controller to enforce its own lack of rotation.