Swift中某个界面横屏设置。

1.在Appdelegate中:

// 是否横屏
var isLandscape = false
// MARK: 是否横屏
extension AppDelegate {
    func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        if isLandscape {
            return .all
        }
        else {
            return .portrait
        }
    }
}

2.在需要横屏的界面:

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        appDelegate.isLandscape = true
        let value = UIInterfaceOrientation.landscapeRight.rawValue
        UIDevice.current.setValue(value, forKey: "orientation")

    }
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        appDelegate.isLandscape = false

         // MARK: - 这句很重要 
        let unknownValue = UIInterfaceOrientation.unknown.rawValue
        UIDevice.current.setValue(unknownValue, forKey: "orientation")

        // 将视图还原成竖屏
        let orientationTarget = UIInterfaceOrientation.portrait.rawValue
        UIDevice.current.setValue(orientationTarget, forKey: "orientation")
    }

    // 是否支持自转 看具体需求
    override var shouldAutorotate: Bool {
        return false
    }
    
    // 设置横屏方向
    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        // 横屏 home键在右
        return .landscapeRight
    }