如何使用tabbar控制器在屏幕区域内设置视图控制器

Question

我已经以编程方式创建了tabbar控制器。下面是我的Tab栏控制器代码。

RecordedAudioListViewController *recordedAudioListViewController = [[RecordedAudioListViewController alloc] initWithNibName:@"RecordedAudioListViewController" bundle:nil];

recordedAudioListViewController.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"Recording" image:spongebob tag:0];
 UINavigationController *firstNavController = [[UINavigationController alloc]initWithRootViewController:recordedAudioListViewController];
    firstNavController.navigationBarHidden = YES;

    RecordViewController *recordViewController = [[RecordViewController alloc]initWithNibName:@"RecordViewController" bundle:nil];

    recordViewController.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"Record" image:patrick tag:1];
    UINavigationController *secondNavController = [[UINavigationController alloc]initWithRootViewController:recordViewController];
    secondNavController.navigationBarHidden = YES;

    SettingViewController *settingViewController = [[SettingViewController alloc]initWithNibName:@"SettingViewController" bundle:nil];
    settingViewController.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"Setting" image:spongebob tag:2];
    UINavigationController *thirdNavController = [[UINavigationController alloc]initWithRootViewController:settingViewController];
    thirdNavController.navigationBarHidden = YES;

    tabBarController = [[UITabBarController alloc] initWithNibName:nil bundle:nil];
    tabBarController.viewControllers = [[NSArray alloc] initWithObjects:firstNavController, secondNavController, thirdNavController, nil];
    tabBarController.delegate = self;
    tabBarController.selectedIndex = 1;

    self.window.rootViewController = tabBarController;
    [self.window makeKeyAndVisible]; 

在下图中，您可以看到视图控制器从屏幕顶部移出。