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
import UIKit
extension UIApplication {
// MARK: Choose keyWindow as per your choice
var currentWindow: UIWindow? {
connectedScenes
.filter({$0.activationState == .foregroundActive})
.map({$0 as? UIWindowScene})
.compactMap({$0})
.first?.windows
.filter({$0.isKeyWindow}).first
}
// MARK: Choose keyWindow as per your choice
var keyWindow: UIWindow? {
UIApplication.shared.windows.first { $0.isKeyWindow }
}
class func topMostViewController(base: UIViewController? = UIApplication.shared.currentWindow?.rootViewController) -> UIViewController? {
if let nav = base as? UINavigationController {
return topMostViewController(base: nav.visibleViewController)
}
if let tab = base as? UITabBarController {
let moreNavigationController = tab.moreNavigationController
if let top = moreNavigationController.topViewController, top.view.window != nil {
return topMostViewController(base: top)
} else if let selected = tab.selectedViewController {
return topMostViewController(base: selected)
}
}
if let presented = base?.presentedViewController {
return topMostViewController(base: presented)
}
return base
}
}
其他回答
import UIKit
extension UIApplication {
// MARK: Choose keyWindow as per your choice
var currentWindow: UIWindow? {
connectedScenes
.filter({$0.activationState == .foregroundActive})
.map({$0 as? UIWindowScene})
.compactMap({$0})
.first?.windows
.filter({$0.isKeyWindow}).first
}
// MARK: Choose keyWindow as per your choice
var keyWindow: UIWindow? {
UIApplication.shared.windows.first { $0.isKeyWindow }
}
class func topMostViewController(base: UIViewController? = UIApplication.shared.currentWindow?.rootViewController) -> UIViewController? {
if let nav = base as? UINavigationController {
return topMostViewController(base: nav.visibleViewController)
}
if let tab = base as? UITabBarController {
let moreNavigationController = tab.moreNavigationController
if let top = moreNavigationController.topViewController, top.view.window != nil {
return topMostViewController(base: top)
} else if let selected = tab.selectedViewController {
return topMostViewController(base: selected)
}
}
if let presented = base?.presentedViewController {
return topMostViewController(base: presented)
}
return base
}
}
iOS13+ //top最多视图控制器
extension UIViewController {
func topMostViewController() -> UIViewController {
if self.presentedViewController == nil {
return self
}
if let navigation = self.presentedViewController as? UINavigationController {
return navigation.visibleViewController!.topMostViewController()
}
if let tab = self.presentedViewController as? UITabBarController {
if let selectedTab = tab.selectedViewController {
return selectedTab.topMostViewController()
}
return tab.topMostViewController()
}
return self.presentedViewController!.topMostViewController()
}
}
extension UIApplication {
func topMostViewController() -> UIViewController? {
return UIWindow.key!.rootViewController?.topMostViewController()
}
}
extension UIWindow {
static var key: UIWindow? {
if #available(iOS 13, *) {
return UIApplication.shared.windows.first { $0.isKeyWindow }
} else {
return UIApplication.shared.keyWindow
}
}
}
//use let vc = UIApplication.shared.topMostViewController()
// End top Most view Controller
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() {
}
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)
}
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
}
