如果没有UINavigationController，我似乎无法得到最顶端的UIViewController。以下是我目前所掌握的:
UIApplication.sharedApplication().keyWindow?.rootViewController?.presentViewController(vc, animated: true, completion: nil)
然而，它似乎没有做任何事情。keyWindow和rootViewController似乎也不是nil值，所以可选的链接应该不是问题。
注意:这样做不是一个好主意。它打破了MVC模式。
当前回答
class func topViewController(controller: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
if let navigationController = controller as? UINavigationController {
return topViewController(controller: navigationController.visibleViewController)
}
if let tabController = controller as? UITabBarController {
if let selected = tabController.selectedViewController {
return topViewController(controller: selected)
}
}
if let presented = controller?.presentedViewController {
return topViewController(controller: presented)
}
return controller
}
其他回答
@AlberZou略有变化，使用计算变量而不是函数
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
}
}
然后说
if let topViewControler = UIApplication.shared.topMostViewController {
... do stuff
}
斯威夫特 5+
声明
func topViewController() -> UIViewController? {
let keyWindow = UIApplication.shared.windows.filter {$0.isKeyWindow}.first
if var topController = keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
return topController
} else {
return nil
}
}
Use
topViewController()?.view.addSubview(UIView())
基于上面的Bob -c:
斯威夫特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;
}
}
}
}
有这个扩展
斯威夫特2。*
extension UIApplication {
class func topViewController(controller: UIViewController? = UIApplication.sharedApplication().keyWindow?.rootViewController) -> UIViewController? {
if let navigationController = controller as? UINavigationController {
return topViewController(navigationController.visibleViewController)
}
if let tabController = controller as? UITabBarController {
if let selected = tabController.selectedViewController {
return topViewController(selected)
}
}
if let presented = controller?.presentedViewController {
return topViewController(presented)
}
return controller
}
}
斯威夫特3
extension UIApplication {
class func topViewController(controller: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
if let navigationController = controller as? UINavigationController {
return topViewController(controller: navigationController.visibleViewController)
}
if let tabController = controller as? UITabBarController {
if let selected = tabController.selectedViewController {
return topViewController(controller: selected)
}
}
if let presented = controller?.presentedViewController {
return topViewController(controller: presented)
}
return controller
}
}
然后你可以在控制器的任何地方使用它
if let topController = UIApplication.topViewController() {
}
在Swift 3中找到可见的viewController
if let viewControllers = window?.rootViewController?.childViewControllers {
let prefs = UserDefaults.standard
if viewControllers[viewControllers.count - 1] is ABCController{
print("[ABCController] is visible")
}
}
这段代码找到最后添加的或最后可见的活动控制器。
我已经在AppDelegate中使用它来查找活动视图控制器
