自定义标签栏控制器不起作用？

Question

我正在尝试构建自定义选项卡栏控制器，但由于某种原因，视图不会切换...初始视图已正确加载。这是我的初始化方法：

- (id)initWithNibName:(NSString *)nibNameOrNil 
           bundle:(NSBundle *)nibBundleOrNil
{
AccountViewController *accountViewController = [[AccountViewController alloc]
                    initWithNibName:@"AccountViewController" bundle:nil];
MoreViewController *moreViewController = [[MoreViewController alloc]
                    initWithNibName:@"MoreViewController" bundle:nil];
BarTabViewController *barTabViewController = [[BarTabViewController alloc]
                    initWithNibName:@"BarTabViewController" bundle:nil];
LocationsViewController *locationsViewController = [[LocationsViewController alloc]
                    initWithNibName:@"LocationsViewController" bundle:nil];

self.viewControllers = [NSArray arrayWithObjects:locationsViewController, accountViewController,
                        barTabViewController, moreViewController, nil];

[self.view addSubview:locationsViewController.view];
self.selectedController = locationsViewController;

    return self;
}

就像我说的，这将正确显示选定的控制器，但是当应用程序启动并且我尝试使用选项卡栏切换视图时，子视图就会变成灰色......我一直在浏览几个教程试图弄清楚这个问题，但似乎我正在做同样的事情。我还检查了 IB 文件以确保我的选项卡连接正确，确实如此。以下是切换项目的代码：

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item
{
    if (item == locationsTabBarItem) {
        UIViewController *locationsController = [viewControllers objectAtIndex:0];
        [self.selectedController.view removeFromSuperview];
        [self.view addSubview:locationsController.view];
        self.selectedController = locationsController;
    }
    else if (item == accountsTabBarItem) {
        UIViewController *accountsController = [viewControllers objectAtIndex:1];
        [self.selectedController.view removeFromSuperview];
        [self.view addSubview:accountsController.view];
        self.selectedController = accountsController;
    }
    else if (item == barTabTabBarItem) {
        UIViewController *barTabController = [viewControllers objectAtIndex:2];
        [self.selectedController.view removeFromSuperview];
        [self.view addSubview:barTabController.view];
        self.selectedController = barTabController;
    }
    else {
        UIViewController *moreController = [viewControllers objectAtIndex:3];
        [self.selectedController.view removeFromSuperview];
        [self.view addSubview:moreController.view];
        self.selectedController = moreController;
    }
}

Answer 1

尝试用这个

 self.tabBarController = [[UITabBarController alloc] init];
    self.tabBarController.selectedIndex = 0;

    self.tabBarController.viewControllers = [NSArray arrayWithObjects:locationsViewController, accountViewController,
                        barTabViewController, moreViewController, nil];
    self.tabBarController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
    [self.navigationController pushViewController:delegate.tabBarController animated:YES];