获取最顶级的UIViewController
获取最顶级的UIViewController
提问于 2014-10-31 11:14:00
如果不访问UINavigationController，我似乎无法获得最高级别的UIViewController。这是我到目前为止所知道的：
UIApplication.sharedApplication().keyWindow?.rootViewController?.presentViewController(vc, animated: true, completion: nil)然而，它似乎什么也做不了。keyWindow和rootViewController似乎也是非空值，所以可选的链接应该不是问题。
注意：做这样的事情不是个好主意。它打破了MVC模式。
回答 27
Stack Overflow用户
回答已采纳
发布于 2014-10-31 11:29:15
presentViewController显示了一个视图控制器。它不返回视图控制器。如果您没有使用UINavigationController，那么您可能正在寻找presentedViewController，并且需要从根开始并向下迭代所显示的视图。
if var topController = UIApplication.sharedApplication().keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
// topController should now be your topmost view controller
}对于Swift 3+：
if var topController = UIApplication.shared.keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
// topController should now be your topmost view controller
}对于iOS 13+
let keyWindow = UIApplication.shared.windows.filter {$0.isKeyWindow}.first
if var topController = keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
// topController should now be your topmost view controller
}Stack Overflow用户
发布于 2015-06-16 12:06:34
具有此扩展名
Swift 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
}
}Swift 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
}
}你可以在你的控制器上的任何地方使用它
if let topController = UIApplication.topViewController() {
}Stack Overflow用户
发布于 2018-06-02 19:03:30
适用于swift 4/5+的，可获得最高的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)
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/26667009
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