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
在SWIFT 5.2中
你可以使用下面的代码:
import UIKit
extension UIWindow {
static func getTopViewController() -> UIViewController? {
if #available(iOS 13, *){
let keyWindow = UIApplication.shared.windows.filter {$0.isKeyWindow}.first
if var topController = keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
return topController
}
} else {
if var topController = UIApplication.shared.keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
return topController
}
}
return nil
}
}
其他回答
在Swift 3中找到可见的viewController
if let viewControllers = window?.rootViewController?.childViewControllers {
let prefs = UserDefaults.standard
if viewControllers[viewControllers.count - 1] is ABCController{
print("[ABCController] is visible")
}
}
这段代码找到最后添加的或最后可见的活动控制器。
我已经在AppDelegate中使用它来查找活动视图控制器
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
}
https://gist.github.com/db0company/369bfa43cb84b145dfd8 我对这个网站上的答案和评论做了一些测试。对我来说，以下方法有效
extension UIViewController {
func topMostViewController() -> UIViewController {
if let presented = self.presentedViewController {
return presented.topMostViewController()
}
if let navigation = self as? UINavigationController {
return navigation.visibleViewController?.topMostViewController() ?? navigation
}
if let tab = self as? UITabBarController {
return tab.selectedViewController?.topMostViewController() ?? tab
}
return self
}
}
extension UIApplication {
func topMostViewController() -> UIViewController? {
return self.keyWindow?.rootViewController?.topMostViewController()
}
}
然后，通过以下方法获取top viewController:
UIApplication.shared.topMostViewController()
var topViewController: UIViewController? {
guard var topViewController = UIApplication.shared.keyWindow?.rootViewController else { return nil }
while let presentedViewController = topViewController.presentedViewController {
topViewController = presentedViewController
}
return topViewController
}
