当您具有复杂的视图层次结构时，事情会变得很混乱，例如具有多个导航控制器和/或选项卡视图控制器。

此实现将其置于各个视图控制器上，以便在它们希望锁定方向时进行设置，而不是依赖于App Delegate通过遍历子视图来找到它们。

斯威夫特3＆4

在AppDelegate中：

/// set orientations you want to be allowed in this property by default
var orientationLock = UIInterfaceOrientationMask.all

func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        return self.orientationLock
}

在其他一些全局struct或helper类中，我在这里创建了AppUtility：

struct AppUtility {

    static func lockOrientation(_ orientation: UIInterfaceOrientationMask) {

        if let delegate = UIApplication.shared.delegate as? AppDelegate {
            delegate.orientationLock = orientation
        }
    }

    /// OPTIONAL Added method to adjust lock and rotate to the desired orientation
    static func lockOrientation(_ orientation: UIInterfaceOrientationMask, andRotateTo rotateOrientation:UIInterfaceOrientation) {

        self.lockOrientation(orientation)

        UIDevice.current.setValue(rotateOrientation.rawValue, forKey: "orientation")
        UINavigationController.attemptRotationToDeviceOrientation()
    }

}

然后在所需的ViewController中，您要锁定方向：

 override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    AppUtility.lockOrientation(.portrait)
    // Or to rotate and lock
    // AppUtility.lockOrientation(.portrait, andRotateTo: .portrait)

}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    // Don't forget to reset when view is being removed
    AppUtility.lockOrientation(.all)
}

如果是iPad或Universal App

确保在“目标设置”->“常规”->“部署信息”中选中了“需要全屏显示”。supportedInterfaceOrientationsFor如果未选中，则不会调用委托。