使用Swift在一个ViewController中强制横向模式

Question

我试图在横向模式下强制应用程序中只有一个视图，我调用：

override func shouldAutorotate() -> Bool {
    print("shouldAutorotate")
    return false
}

override func supportedInterfaceOrientations() -> Int {
    print("supportedInterfaceOrientations")
    return Int(UIInterfaceOrientationMask.LandscapeLeft.rawValue)
}

override func preferredInterfaceOrientationForPresentation() -> UIInterfaceOrientation {
    return UIInterfaceOrientation.LandscapeLeft
}

视图以纵向模式启动，并在更改设备方向时保持旋转。永远不会调用shouldAutorotate（）方法。

任何帮助都将不胜感激。

Answer 1

Swift 4，在iOS 11中测试

您可以在项目目标中指定方向-

AppDelegate

    var myOrientation: UIInterfaceOrientationMask = .portrait
    func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        return myOrientation
    }

LandScpaeViewController

override func viewDidLoad() {
        super.viewDidLoad()
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        appDelegate.myOrientation = .landscape
}

点击按钮

let appDelegate = UIApplication.shared.delegate as! AppDelegate
 appDelegate.myOrientation = .portrait

就是这样。：）

Answer 2

override func viewDidLoad() {
    super.viewDidLoad()
    let value = UIInterfaceOrientation.landscapeLeft.rawValue
    UIDevice.current.setValue(value, forKey: "orientation")
}

override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
    return .landscapeLeft
}

override var shouldAutorotate: Bool {
    return true
}

如果您的视图嵌入到导航控制器中，那么仅上述操作是行不通的。您必须在类定义之后通过以下扩展进行级联。

extension UINavigationController {

override open var shouldAutorotate: Bool {
    get {
        if let visibleVC = visibleViewController {
            return visibleVC.shouldAutorotate
        }
        return super.shouldAutorotate
    }
}

override open var preferredInterfaceOrientationForPresentation: UIInterfaceOrientation{
    get {
        if let visibleVC = visibleViewController {
            return visibleVC.preferredInterfaceOrientationForPresentation
        }
        return super.preferredInterfaceOrientationForPresentation
    }
}

override open var supportedInterfaceOrientations: UIInterfaceOrientationMask{
    get {
        if let visibleVC = visibleViewController {
            return visibleVC.supportedInterfaceOrientations
        }
        return super.supportedInterfaceOrientations
    }
}}

override func viewDidLoad() {
    super.viewDidLoad()
    let value = UIInterfaceOrientation.landscapeLeft.rawValue
    UIDevice.current.setValue(value, forKey: "orientation")
}

private func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
    return UIInterfaceOrientationMask.landscapeLeft
}

private func shouldAutorotate() -> Bool {
    return true
}

Answer 3

这可能对其他人有用，我找到了一种强制以横向模式启动视图的方法：

把这个放在viewddLoad（）中：

let value = UIInterfaceOrientation.landscapeLeft.rawValue
UIDevice.current.setValue(value, forKey: "orientation")

和

override var shouldAutorotate: Bool {
    return true
}