我正在尝试使用应用程序委托中的以下代码将两个 NavBar 控制器嵌入到 UITabbarController 中：
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
[window makeKeyAndVisible];
// Configure and show the window.
FirstViewController *firstController = [[FirstViewController alloc] initWithNibName:nil bundle:NULL];
self.firstNav = [[UINavigationController alloc] initWithRootViewController:firstController];
SecondTableViewController *anotherOne = [[SecondTableViewController alloc] initWithNibName:nil bundle:NULL];
self.anotherNav = [[UINavigationController alloc] initWithRootViewController:anotherOne];
NSArray *twoViewControllers = [[NSArray alloc]initWithObjects:self.anotherNav,self.firstNav, nil];
self.tabBarController = [[UITabBarController alloc]init];
[self.tabBarController setViewControllers:twoViewControllers];
[window addSubview:self.tabBarController.view];
[window setRootViewController:tabBarController];
return YES;
}
这两个选项卡显示正常，带有它们的名称，但我只能选择第一个选项卡，第二个选项卡始终显示为灰色并且不响应触摸事件。我将 navController 分配反转到 Tabbar 中（即在数组 twoViewControllers 中），并且每个视图都显示良好（在第一个选项卡中）。
应用程序委托未实现 UITabbarDelegate 和 uiTabBarControllerDelegate。我不使用故事板。
第二个标签总是灰色的有什么明显的原因吗？
示例代码：这里只是 Apple 的 Locations 教程（带有 ARC）
然后改变：
- (void)applicationDidFinishLaunching:(UIApplication *)application {}
为了
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// Configure and show the window.
RootViewController *cont1 = [[RootViewController alloc] initWithNibName:nil bundle:NULL];
RootViewController *cont2 = [[RootViewController alloc] initWithNibName:nil bundle:NULL];
NSManagedObjectContext *context = [self managedObjectContext];
if (!context) {
// Handle the error.
}
cont1.managedObjectContext = context;
cont2.managedObjectContext = context;
UINavigationController *aNav1 = [[UINavigationController alloc] initWithRootViewController:cont1];
UINavigationController *aNav2 = [[UINavigationController alloc] initWithRootViewController:cont2];
NSArray *twoViewControllers = [[NSArray alloc]initWithObjects:aNav1,aNav2, nil];
self.tabBarController = [[UITabBarController alloc]init];
[self.tabBarController setViewControllers:twoViewControllers];
//[window addSubview:[tabBarController view]];
[window setRootViewController:tabBarController];
[window makeKeyAndVisible];
}
并将@interface LocationAppDelegate ...@end 替换为
@interface LocationsAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UITabBarController *tabBarController;
NSPersistentStoreCoordinator *persistentStoreCoordinator;
NSManagedObjectModel *managedObjectModel;
NSManagedObjectContext *managedObjectContext;
}
@property (nonatomic, strong) IBOutlet UIWindow *window;
@property (nonatomic, strong) UITabBarController *tabBarController;
- (IBAction)saveAction:sender;
@property (nonatomic, strong, readonly) NSManagedObjectModel *managedObjectModel;
@property (nonatomic, strong, readonly) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, strong, readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator;
@property (weak, nonatomic, readonly) NSString *applicationDocumentsDirectory;
@end
并编译运行。