Get top most UIViewController

Question

I can't seem to get the top most UIViewController without access to a UINavigationController. Here is what I have so far:

UIApplication.sharedApplication().keyWindow?.rootViewController?.presentViewController(vc, animated: true, completion: nil)

However, it does not seem to do anything. The keyWindow and rootViewController seem to be non-nil values too, so the optional chaining shouldn't be an issue.

NOTE: It is a bad idea to do something like this. It breaks the MVC pattern.

Answer 1

extension UIWindow {

    func visibleViewController() -> UIViewController? {
        if let rootViewController: UIViewController = self.rootViewController {
            return UIWindow.getVisibleViewControllerFrom(vc: rootViewController)
        }
        return nil
    }

    static func getVisibleViewControllerFrom(vc:UIViewController) -> UIViewController {
        if let navigationController = vc as? UINavigationController,
            let visibleController = navigationController.visibleViewController  {
            return UIWindow.getVisibleViewControllerFrom( vc: visibleController )
        } else if let tabBarController = vc as? UITabBarController,
            let selectedTabController = tabBarController.selectedViewController {
            return UIWindow.getVisibleViewControllerFrom(vc: selectedTabController )
        } else {
            if let presentedViewController = vc.presentedViewController {
                return UIWindow.getVisibleViewControllerFrom(vc: presentedViewController)
            } else {
                return vc
            }
        }
    }
}

Usage:

if let topController = window.visibleViewController() {
    println(topController)
}

Answer 2

For swift4 to find topmost viewController

extension UIApplication {
    class func getTopMostViewController(base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
        if let nav = base as? UINavigationController {
            return getTopMostViewController(base: nav.visibleViewController)
        }
        if let tab = base as? UITabBarController {
            if let selected = tab.selectedViewController {
                return getTopMostViewController(base: selected)
            }
        }
        if let presented = base?.presentedViewController {
            return getTopMostViewController(base: presented)
        }
        return base
    }
 }

How to use

if let topVC = UIApplication.getTopMostViewController() {
   topVC.view.addSubview(forgotPwdView)
}

Answer 3

Slight Variation on @AlberZou using a computed variable rather than a function

extension UIViewController {
  var topMostViewController : UIViewController {

    if let presented = self.presentedViewController {
      return presented.topMostViewController
    }

    if let navigation = self as? UINavigationController {
      return navigation.visibleViewController?.topMostViewController ?? navigation
    }

    if let tab = self as? UITabBarController {
      return tab.selectedViewController?.topMostViewController ?? tab
    }

    return self
  }
}

extension UIApplication {
  var topMostViewController : UIViewController? {
    return self.keyWindow?.rootViewController?.topMostViewController
  }
}

Then say

If let topViewControler = UIApplication.shared.topMostViewController {
    ... do stuff
}

Answer 4

presentViewController shows a view controller. It doesn't return a view controller. If you're not using a UINavigationController, you're probably looking for presentedViewController and you'll need to start at the root and iterate down through the presented views.

if var topController = UIApplication.sharedApplication().keyWindow?.rootViewController {
    while let presentedViewController = topController.presentedViewController {
        topController = presentedViewController
    }

    // topController should now be your topmost view controller
}

For Swift 3+:

if var topController = UIApplication.shared.keyWindow?.rootViewController {
    while let presentedViewController = topController.presentedViewController {
        topController = presentedViewController
    }

    // topController should now be your topmost view controller
}

Answer 5

Where did you put the code in?

I try your code in my demo, I found out, if you put the code in

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { 

will fail, because key window have been setting yet.

But I put your code in some view controller's

override func viewDidLoad() {

It just works.

Answer 6

Based on Bob -c above:

Swift 3.0

extension UIWindow {


    func visibleViewController() -> UIViewController? {
        if let rootViewController: UIViewController  = self.rootViewController {
            return UIWindow.getVisibleViewControllerFrom(vc: rootViewController)
        }
        return nil
    }

    class func getVisibleViewControllerFrom(vc:UIViewController) -> UIViewController {

        if vc.isKind(of: UINavigationController.self) {

            let navigationController = vc as! UINavigationController
            return UIWindow.getVisibleViewControllerFrom( vc: navigationController.visibleViewController!)

        } else if vc.isKind(of: UITabBarController.self) {

            let tabBarController = vc as! UITabBarController
            return UIWindow.getVisibleViewControllerFrom(vc: tabBarController.selectedViewController!)

        } else {

            if let presentedViewController = vc.presentedViewController {

                return UIWindow.getVisibleViewControllerFrom(vc: presentedViewController)

            } else {

                return vc;
            }
        }
    }
}