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
你可以在AppDelegate中定义一个UIViewController变量，并在每个viewWillAppear中设置这个变量为self。(然而，dianz的答案是最好的答案。)
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
let appDel = UIApplication.sharedApplication().delegate as! AppDelegate
appDel.currentVC = self
}
其他回答
试试这个
let topVisibleVC = UIApplication.shared.keyWindow?.rootViewController?.visibleViewController
你可以在AppDelegate中定义一个UIViewController变量，并在每个viewWillAppear中设置这个变量为self。(然而，dianz的答案是最好的答案。)
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
let appDel = UIApplication.sharedApplication().delegate as! AppDelegate
appDel.currentVC = self
}
对于swift 4 / 5 +获取topmost viewController
// MARK: UIApplication extensions
extension UIApplication {
class func getTopViewController(base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
if let nav = base as? UINavigationController {
return getTopViewController(base: nav.visibleViewController)
} else if let tab = base as? UITabBarController, let selected = tab.selectedViewController {
return getTopViewController(base: selected)
} else if let presented = base?.presentedViewController {
return getTopViewController(base: presented)
}
return base
}
}
如何使用
if let topVC = UIApplication.getTopViewController() {
topVC.view.addSubview(forgotPwdView)
}
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
}
extension UIApplication {
public var mainKeyWindow: UIWindow? {
if #available(iOS 13, *) {
return UIApplication.shared.connectedScenes
.filter { $0.activationState == .foregroundActive }
.first(where: { $0 is UIWindowScene })
.flatMap { $0 as? UIWindowScene }?.windows
.first(where: \.isKeyWindow)
} else {
return UIApplication.shared.windows.first { $0.isKeyWindow }
}
}
public var rootViewController: UIViewController? {
guard let keyWindow = UIApplication.shared.mainKeyWindow, let rootViewController = keyWindow.rootViewController else {
return nil
}
return rootViewController
}
public func topViewController(controller: UIViewController? = UIApplication.shared.rootViewController) -> UIViewController? {
if controller == nil {
return topViewController(controller: rootViewController)
}
if let navigationController = controller as? UINavigationController {
return topViewController(controller: navigationController.visibleViewController)
}
if let tabController = controller as? UITabBarController {
if let selectedViewController = tabController.selectedViewController {
return topViewController(controller: selectedViewController)
}
}
if let presentedViewController = controller?.presentedViewController {
return topViewController(controller: presentedViewController)
}
return controller
}
}
Swift 5.2及以上版本
