UITabBar Fuctionality

Question

TabBar不應該啓用任何標籤，直到用戶點擊任何一個標籤， 下面是我寫的代碼來顯示標籤欄，但問題默認情況下它顯示第一個標籤。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 
// Override point for customization after application launch. 
self.window.backgroundColor = [UIColor whiteColor]; 
[self.window makeKeyAndVisible]; 

    PeopleViewController *peopleViewController = [[PeopleViewController alloc] init]; 
UINavigationController *nav1 = [[UINavigationController alloc] initWithRootViewController:peopleViewController]; 
[peopleViewController setTitle:@"People"]; 

EventsViewController *eventsViewController = [[EventsViewController alloc] init]; 
UINavigationController *nav2 = [[UINavigationController alloc]initWithRootViewController:eventsViewController]; 
[eventsViewController setTitle:@"Events"]; 

ActiveViewController *activeViewController = [[ActiveViewController alloc] init]; 
UINavigationController *nav3 = [[UINavigationController alloc]initWithRootViewController:activeViewController]; 
[activeViewController setTitle:@"Active"]; 

MoreViewController *moreViewController = [[MoreViewController alloc] init]; 
UINavigationController *nav4 = [[UINavigationController alloc] initWithRootViewController:moreViewController]; 
[moreViewController setTitle:@"More"]; 

NSArray *arrViewControllers = [[NSArray alloc] initWithObjects:nav1,nav2,nav3,nav4, nil]; 

[tabBarController setViewControllers:arrViewControllers]; 
[self.window addSubview:tabBarController.view]; 
    return YES; 

} 

Answer 1

爲標籤欄（例如theTabBar）和使用以下代碼創建一個IBOutlet：

[theTabBar setSelectedItem:nil];

Answer 2

這是UITabBarController默認行爲，默認情況下第一標籤被選中。 您可以選擇在第一個實例中選擇其他選項卡，但不能將選中的默認選項更改爲空。

[tabBarController setSelectedIndex:0]; 

默認情況下，選定索引爲0，這是第一個選項卡，您可以根據您的要求將其更改爲1,2,3。