我正在使用以下扩展来查找 top most ViewController .
如果出现警报，上面的代码会给出 UIAlertController。
如何在 UIAlertController 下获取顶 View Controller ？
最佳答案
像下面这样创建一个 UIApplication 扩展，UIApplication.topViewController() 将返回 UIAlertController 下最顶层的 UIViewController
iOS 13+
extension UIApplication {
class func topViewController(controller: UIViewController? = UIApplication.shared.windows.first?.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)
}
if let alert = controller as? UIAlertController {
if let navigationController = alert.presentingViewController as? UINavigationController {
return navigationController.viewControllers.last
}
return alert.presentingViewController
}
return controller
}
}
iOS 12-
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)
}
if let alert = controller as? UIAlertController {
if let navigationController = alert.presentingViewController as? UINavigationController {
return navigationController.viewControllers.last
}
return alert.presentingViewController
}
return controller
}
}
关于ios - UIAlertController 下最顶层的 ViewController，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36284476/