How to lock orientation of one view controller to portrait mode only in Swift

Question

Since my app got support for all orientation. I would like to lock only portrait mode to specific UIViewController.

e.g. assume it was Tabbed Application and when Si

Answer 1

A bunch of great answers in this thread, but none quite matched my needs. I have a tabbed app with navigation controllers in each tab, and one view needed to rotate, while the others needed to be locked in portrait. The navigation controller wasn't resizing it's subviews properly, for some reason. Found a solution (in Swift 3) by combining with this answer, and the layout issues disappeared. Create the struct as suggest by @bmjohns:

import UIKit

struct OrientationLock {

    static func lock(to orientation: UIInterfaceOrientationMask) {
        if let delegate = UIApplication.shared.delegate as? AppDelegate {
            delegate.orientationLock = orientation
        }
    }

    static func lock(to orientation: UIInterfaceOrientationMask, andRotateTo rotateOrientation: UIInterfaceOrientation) {
        self.lock(to: orientation)
        UIDevice.current.setValue(rotateOrientation.rawValue, forKey: "orientation")
    }
} 

Then subclass UITabBarController:

    import UIKit

class TabBarController: UITabBarController, UITabBarControllerDelegate {
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.delegate = self
    }

    func tabBarControllerSupportedInterfaceOrientations(_ tabBarController: UITabBarController) -> UIInterfaceOrientationMask {
        if tabBarController.selectedViewController is MyViewControllerNotInANavigationControllerThatShouldRotate {
            return .allButUpsideDown
        } else if let navController = tabBarController.selectedViewController as? UINavigationController, navController.topViewController is MyViewControllerInANavControllerThatShouldRotate {
            return .allButUpsideDown
        } else {
            //Lock view that should not be able to rotate
            return .portrait
        }
    }

    func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
        if viewController is MyViewControllerNotInANavigationControllerThatShouldRotate {
            OrientationLock.lock(to: .allButUpsideDown)
        } else if let navController = viewController as? UINavigationController, navController.topViewController is MyViewControllerInANavigationControllerThatShouldRotate {
            OrientationLock.lock(to: .allButUpsideDown)
        } else {
            //Lock orientation and rotate to desired orientation
            OrientationLock.lock(to: .portrait, andRotateTo: .portrait)
        }
        return true
    }
}

Don't forget to change the class of the TabBarController in the storyboard to the newly created subclass.