以编程方式更改方向无法正常工作 [英] Changing orientations programmatically does not work fine

问题描述

我的整个应用程序处于portrait模式.我只想在landscape模式下使用一个视图控制器(左).

My whole application is in portrait mode. I just want to use one view controller in landscape mode (left).

func application(application: UIApplication, supportedInterfaceOrientationsForWindow window: UIWindow?) -> UIInterfaceOrientationMask 
{
    if let _navigationController = window?.rootViewController as? UINavigationController {

        if _navigationController.topViewController is FullScreenPlayerVC {

            return UIInterfaceOrientationMask.LandscapeLeft
        }
    }

    return UIInterfaceOrientationMask.Portrait
}

这是我的控制器A

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

override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask
{
    return UIInterfaceOrientationMask.Portrait
}

现在我按下控制器B.这是我的控制器B

Now i push Controller B. This is my controller B

override func viewDidAppear(animated: Bool)
{
    super.viewDidAppear(animated)

    let value = UIInterfaceOrientation.LandscapeLeft.rawValue
    UIDevice.currentDevice().setValue(value, forKey: "orientation")
 }

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

override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask
{
    return UIInterfaceOrientationMask.Landscape
}

当我将控制器B保持在纵向模式时按控制器B时，它按我的要求工作，但是如果我已经将手机保持在横向模式中，则可以按我的要求进行操作.

It works as per my requirement when i push controller B while holding my device in portrait mode but if i am holding my phone in landscape left already.

它没有执行所需的操作.搜索了很多关于它，但是还找不到解决方案.

It does not perform desired action. Searched a lot about it but not able to find the solution yet.

我尝试了许多解决方案，但没有任何效果.

I have tried many solutions but nothings working fine.

推荐答案

这是针对您的问题和其他相关问题的通用解决方案.

This is a generic solution for your problem and others related.

1.创建辅助类UIHelper并使用以下方法:

    /**This method returns top view controller in application  */
    class func topViewController() -> UIViewController?
    {
        let helper = UIHelper()
        return helper.topViewControllerWithRootViewController(rootViewController: UIApplication.shared.keyWindow?.rootViewController)
    }

    /**This is a recursive method to select the top View Controller in a app, either with TabBarController or not */
    private func topViewControllerWithRootViewController(rootViewController:UIViewController?) -> UIViewController?
    {
        if(rootViewController != nil)
        {
            // UITabBarController
            if let tabBarController = rootViewController as? UITabBarController,
                let selectedViewController = tabBarController.selectedViewController {
                return self.topViewControllerWithRootViewController(rootViewController: selectedViewController)
            }

            // UINavigationController
            if let navigationController = rootViewController as? UINavigationController ,let visibleViewController = navigationController.visibleViewController {
                return self.topViewControllerWithRootViewController(rootViewController: visibleViewController)
            }

            if ((rootViewController!.presentedViewController) != nil) {
                let presentedViewController = rootViewController!.presentedViewController;
                return self.topViewControllerWithRootViewController(rootViewController: presentedViewController!);
            }else
            {
                return rootViewController
            }
        }

        return nil
    }

2.根据您的期望行为创建协议，因为您的具体情况将是横向的.

协议的方向是IsOnlyLandscape {}

protocol orientationIsOnlyLandscape {}

注意:如果需要，可将其添加到UIHelper类的顶部.

Nota: If you want, add it in the top of UIHelper Class.

3.扩展您的View Controller

在您的情况下:

class B_ViewController: UIViewController,orientationIsOnlyLandscape {

   ....

}

4.在应用程序委托类中，添加以下方法:

 func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        let presentedViewController = UIHelper.topViewController()
        if presentedViewController is orientationIsOnlyLandscape {
            return .landscape
        }
        return .portrait
    }

最后的注释:

• 如果您有更多的课程是横向模式，只需扩展 协议.
• 如果您希望视图控制器具有其他行为，请创建其他协议并遵循相同的结构.
• 此示例解决了推后方向改变的问题 查看控制器

• If you that more class are in landscape mode, just extend that protocol.
• If you want others behaviors from view controllers, create other protocols and follow the same structure.
• This example solves the problem with orientations changes after push view controllers

这篇关于以编程方式更改方向无法正常工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！