因为我的应用程序支持所有方向。我想仅将纵向模式锁定到特定的 UIViewController。
例如假设它是选项卡式应用程序，并且当登录视图以模态方式出现时，我只希望登录视图仅处于纵向模式，无论用户如何旋转设备或当前设备方向如何
当你有一个复杂的视图层次结构时，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。
此实现将其放在各个视图控制器上以设置它们何时想要锁定方向，而不是依赖应用程序委托通过迭代子视图来找到它们。
斯威夫特 3、4、5
在应用程序委托中：
/// 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
}
在其他一些全局结构或帮助器类中，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 中您想要锁定方向：
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 或通用应用程序
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.
