如何仅在 Swift 中将一个视图控制器的方向锁定为纵向模式

发布于01月24日

因为我的应用程序支持所有方向.我只想将肖像模式锁定到特定的UIViewController.

e、 g.假设它是选项卡式应用程序，当SignIn View以模式显示时，我只希望SignIn View处于纵向模式，无论用户如何旋转设备或当前设备方向如何

推荐答案

当您有一个复杂的视图层次 struct 时，事情可能会变得非常混乱，比如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，以设置它们希望锁定方向的时间，而不是依赖应用程序委托通过迭代子视图来查找方向.

Swift 3, 4, 5

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 或助手类中，我创建了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，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)
}

If iPad or Universal App

Make sure that "Requires full screen" is checked in Target Settings -> General -> Deployment Info. supportedInterfaceOrientationsFor delegate will not get called if that is not checked.