xcode 在应用程序委托中弹出到根视图控制器
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/12625249/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Pop to root view controller in app delegate
提问by Travis M.
I have an app that someone logs into and if they launch it after sending it to the background for more than 10 minutes I pop up a nice little "session expired" alert and send them to the root view controller (login page).
我有一个应用程序，有人登录，如果他们在将它发送到后台超过 10 分钟后启动它，我会弹出一个漂亮的小“会话已过期”警报并将它们发送到根视图控制器（登录页面）。
Everything works great but I don't know how to pop to the root view controller in my navigation controller stack from the app delegate's applicationWillEnterForeground: method.
一切正常，但我不知道如何从应用程序委托的 applicationWillEnterForeground: 方法弹出到导航控制器堆栈中的根视图控制器。
I tried saving off the navigationController onto an appDelegate variable but I wonder if the app is in the background for several days, if iOS starts freeing some variables, as I get an error in this method at that time.
我尝试将 navigationController 保存到 appDelegate 变量上，但我想知道该应用程序是否在后台运行了几天，iOS 是否开始释放一些变量，因为当时我在此方法中遇到错误。
Any ideas?
有任何想法吗？
回答by Dan F
If the navigation controller is your application's root view controller, then you can get it like:
如果导航控制器是您应用程序的根视图控制器，那么您可以像这样获得它：
UINavigationController *myNavCon = (UINavigationController*)self.window.rootViewController;
where selfis in the app delegate
在self应用程序委托中的位置
回答by mhrrt
Just to make things more clear one can use following to pop to rootviewcontroller from AppDelegate
只是为了让事情更清楚，可以使用以下内容从 AppDelegate 弹出到 rootviewcontroller
UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
[navigationController popToRootViewControllerAnimated:YES];
Here self is app delegate.
这里 self 是应用程序委托。
