xcode viewDidUnload , viewWillDisappear 未在 tabBarContoller 中调用
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viewDidUnload ,viewWillDisappear not called in tabBarContoller
提问by mrugen
I am making a view based application in which the first controller is viewcontroller there is login screen ,after login the next view is tabbar controller and I have 2 tabbar items on that tabbar .
Until this everything works fine . Now when i switch between these two views the viewWillDisappear, viewDidUnloadis not called of previous tab clicked .
我正在制作一个基于视图的应用程序，其中第一个控制器是 viewcontroller 有登录屏幕，登录后下一个视图是标签栏控制器，我在该标签栏上有 2 个标签栏项目。直到这一切正常。现在，当我在这两个视图之间切换时viewWillDisappear，viewDidUnload不会调用之前单击的选项卡。
P.S.Even the viewwillAppear was not called ,which i called it with the Default Notification. Don't know what the issues are. Hope I am clear with my question.
PSE甚至没有调用viewwillAppear，我用默认通知调用了它。不知道是什么问题。希望我清楚我的问题。
回答by sergio
First of all, when switching view in a UITabBarController, the viewDidUnloadfunction is not called because the view is not actually unloaded. So, this is normal.
首先，在UITabBarController中切换视图时，该viewDidUnload函数没有被调用，因为视图实际上并没有被卸载。所以，这是正常的。
What should work out of the box is viewWillAppear/viewDidDisappear. But there is a catch.
Depending on how you show your views, it might be that viewWillAppear/viewDidDisappearare not called by the framework for you. For example, this happens if you add your view as a subview, but there are more cases. I don't know how you display your tab bar, so cannot say anything more specific about it.
应该开箱即用的是viewWillAppear/ viewDidDisappear。但是有一个问题！根据您显示视图的方式，框架可能不会为您调用viewWillAppear/ viewDidDisappear。例如，如果您将视图添加为子视图，就会发生这种情况，但还有更多情况。我不知道你如何显示你的标签栏，所以不能说更具体的。
The easy solution I suggest to fix this is overriding the tabBarController:didSelectViewController:selector in you tab bar controller delegate. From there you could implement you own logic or call viewDidDisappear.
我建议解决此问题的简单解决方案是覆盖tabBarController:didSelectViewController:选项卡栏控制器委托中的选择器。从那里你可以实现你自己的逻辑或调用viewDidDisappear.
回答by Rakesh Bhatt
You should put your TabBar controller in MainWindow.xib.
您应该将 TabBar 控制器放在 MainWindow.xib 中。
First when you show loginscreen you will add your RootViewController like this:
首先，当您显示 loginscreen 时，您将像这样添加 RootViewController：
[self.window addSubview:self.rootview.view];
And when login is complete you can remove your RootViewController from mainwindow and add TabBarController in the mainwindow like this:
登录完成后，您可以从主窗口中删除 RootViewController 并在主窗口中添加 TabBarController，如下所示：
[self.rootview.view removeFromSuperview];
[self.window addSubview:self.tabBarController.view];
回答by ThomasW
Do you have a UINavigationController? You don't refer to one. If you aren't using a UINavigationController then it is likely that your UITabBarController isn't getting set up properly as the topViewController.
你有 UINavigationController 吗？你没有提到一个。如果您没有使用 UINavigationController，那么您的 UITabBarController 可能没有正确设置为 topViewController。
