ios - 在标签IOS之间跳转时ViewController变为空白

Question

我在由 TabBarController 驱动的 uiNavigationControllers 中嵌入了 uiViewControllers。大多数情况下，当我在选项卡之间移动时一切正常，但在随机跳转到第一个选项卡时，屏幕会变为空白(黑色)。 tabBar 仍然可见，我可以跳转到其他两个选项卡，但第一个选项卡仍然是空白的。这仅发生在我的 iPhone 上，而不是模拟器中。我的 appdelegate 看起来像下面的代码，有什么想法吗？

UITabBarController *tabBarController = (UITabBarController *)self.window.rootViewController;

UITabBar *tabBar = tabBarController.tabBar;
UITabBarItem *tabBarItem1 = [tabBar.items objectAtIndex:0];
UITabBarItem *tabBarItem2 = [tabBar.items objectAtIndex:1];
UITabBarItem *tabBarItem3 = [tabBar.items objectAtIndex:2];

tabBarItem1.title = @"Tab 1";
tabBarItem2.title = @"Tab 2";
tabBarItem3.title = @"Tab 3";

[tabBarItem1 setImage:[[UIImage imageNamed:@"tab1.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
[tabBarItem1 setSelectedImage:[[UIImage imageNamed:@"tab1a.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
[tabBarItem2 setImage:[[UIImage imageNamed:@"tab2a.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
[tabBarItem2 setSelectedImage:[[UIImage imageNamed:@"tab2a.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
[tabBarItem3 setImage:[[UIImage imageNamed:@"tab3.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
[tabBarItem3 setSelectedImage:[[UIImage imageNamed:@"tab3a.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];

    [[UITabBar appearance] setTintColor:[UIColor colorWithRed:207/255.0 green:83/255.0 blue:0/255.0 alpha:1.0]];

[[UINavigationBar appearance] setBarTintColor:[UIColor colorWithRed:207/255.0 green:83/255.0 blue:0/255.0 alpha:1.0]];

[[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil] setTintColor:[UIColor whiteColor]];
[UINavigationBar appearance].titleTextAttributes = @{NSForegroundColorAttributeName: [UIColor whiteColor]};

UINavigationController *firstVCnav = [[tabBarController viewControllers] objectAtIndex:0];
UINavigationController *secondVCnav = [[tabBarController viewControllers] objectAtIndex:1];
UINavigationController *thirdVCnav = [[tabBarController viewControllers] objectAtIndex:2];

MyFirstVC *oneVC = [[firstVCnav viewControllers] objectAtIndex:0];
oneVC.managedObjectContext = self.managedObjectContext;

MySecondVC *twoVC = [[secondVCnav viewControllers] objectAtIndex:0];
twoVC.managedObjectContext = self.managedObjectContext;

MyThirdVC *thirdVC = [[thirdVCnav viewControllers] objectAtIndex:0];
thirdVC.managedObjectContext = self.managedObjectContext;

return YES;

Answer 1

从另一个论坛我收到了一个提示，检查我是否使用了预先配置了 View Controller 设置的 Nib 。
我确实在 View Controller 中有一个 Nib 引用，因为我删除了它，所以问题没有发生，但是由于随机/罕见问题，如果问题再次出现，我将监控并更新。