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
太多口味了，但都不是一种反复精心制作的。结合前面的内容:
func topMostController() -> UIViewController? {
var from = UIApplication.shared.keyWindow?.rootViewController
while (from != nil) {
if let to = (from as? UITabBarController)?.selectedViewController {
from = to
} else if let to = (from as? UINavigationController)?.visibleViewController {
from = to
} else if let to = from?.presentedViewController {
from = to
} else {
break
}
}
return from
}
其他回答
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())
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
}
}
}
}
用法:
if let topController = window.visibleViewController() {
println(topController)
}
基于Dianz的答案，Objective-C版本
- (UIViewController *) topViewController {
UIViewController *baseVC = UIApplication.sharedApplication.keyWindow.rootViewController;
if ([baseVC isKindOfClass:[UINavigationController class]]) {
return ((UINavigationController *)baseVC).visibleViewController;
}
if ([baseVC isKindOfClass:[UITabBarController class]]) {
UIViewController *selectedTVC = ((UITabBarController*)baseVC).selectedViewController;
if (selectedTVC) {
return selectedTVC;
}
}
if (baseVC.presentedViewController) {
return baseVC.presentedViewController;
}
return baseVC;
}
试试这个
let topVisibleVC = UIApplication.shared.keyWindow?.rootViewController?.visibleViewController
对于Swift 5+， iOS 13 +
extension UIViewController {
static func topMostViewController() -> UIViewController? {
if #available(iOS 13.0, *) {
let keyWindow = UIApplication.shared.windows.filter {$0.isKeyWindow}.first
return keyWindow?.rootViewController?.topMostViewController()
}
return UIApplication.shared.keyWindow?.rootViewController?.topMostViewController()
}
func topMostViewController() -> UIViewController? {
if let navigationController = self as? UINavigationController {
return navigationController.topViewController?.topMostViewController()
}
else if let tabBarController = self as? UITabBarController {
if let selectedViewController = tabBarController.selectedViewController {
return selectedViewController.topMostViewController()
}
return tabBarController.topMostViewController()
}
else if let presentedViewController = self.presentedViewController {
return presentedViewController.topMostViewController()
}
else {
return self
}
}
}
用法:
当你在没有UIViewController实例的情况下获取topMostViewController时
guard let viewController = UIViewController.topMostViewController() else { return }
print(viewController)
当你获取UIViewController实例的topMostViewController时
let yourVC = UIViewController()
guard let vc = yourVC.topMostViewController() else { return }
print(vc)
