UINavigationController 在 UITabBarController 的 moreNavigationController 中不起作用

Question

我正在应用程序中处理 UINavigationControllers，所有这些都由 UITabBarController 处理。一切工作正常，直到我的控制器落入自动生成的“更多”选项卡。

我在简单的示例中重现了该问题。我做错了什么吗？我想不通。

感谢您的帮助。

#import <UIKit/UIKit.h>

@interface testAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate>
{
    UIWindow *window;
    UITabBarController *tabBarController;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
@end

@implementation testAppDelegate
@synthesize window, tabBarController;

- (void)applicationDidFinishLaunching:(UIApplication *)application
{
    tabBarController = [[UITabBarController alloc] initWithNibName:nil bundle:nil];

    UINavigationController *ctrl1 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl1.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFeatured tag:1] autorelease];

    UINavigationController *ctrl2 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl2.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFavorites tag:2] autorelease];

    UINavigationController *ctrl3 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl3.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemBookmarks tag:3] autorelease];

    UINavigationController *ctrl4 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl4.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemContacts tag:4] autorelease];

    // This one won't work
    UINavigationController *ctrl5 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl5.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemMostRecent tag:5] autorelease];

    // This one will work
    UIViewController *ctrl6 = [[[UIViewController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl6.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemDownloads tag:6] autorelease];

    tabBarController.viewControllers = [NSArray arrayWithObjects:ctrl1, ctrl2, ctrl3, ctrl4, ctrl5, ctrl6, nil];

    [window addSubview:tabBarController.view];
    [window makeKeyAndVisible];
}

- (void)dealloc
{
    [tabBarController release];
    [window release];
    [super dealloc];
}

@end

Answer 1

简短的回答：你不能嵌套导航控制器

较长的回答：你做错了。创建你想要的东西的更好方法是这样的：

NSMutableArray *viewControllers = [NSMutableArray array];

[viewControllers addObject:[[[ConverterViewController alloc] init] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[CurrencyViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[HistoryViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[SetupViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[HelpViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[LinksViewController alloc] init] autorelease]];

self.viewControllers = viewControllers;
self.customizableViewControllers = [viewControllers arrayByRemovingFirstObject];


@implementation HelpViewController

#pragma mark -
#pragma mark Initialization

- (id)init
{
    if ((self = [super initWithNibName:@"HelpView" bundle:nil]) != nil) {
        self.title = NSLocalizedString(@"Help", @"Help"); 
        self.tabBarItem.image = [UIImage imageNamed:@"question.png"];
    }

    return self;
}

Answer 2

我认为问题可能是您直接使用导航控制器来推送新视图。像这样：

[ctrl4 pushViewController:next animated:true];

但是，如果您在“更多”选项卡中，则另一个导航控制器处于活动状态。您必须始终使用当前显示的视图控制器的 navigationController 属性来获取当前的导航控制器。

通过这种方式，导航控制器可以在选项卡栏控制器内正常工作。

Answer 3

当您在 UITabBarController 上设置 viewControllers 属性时，它将自动将视图控制器 5 及以上的导航控制器替换为 moreNavigationController。

我在自定义标签栏上处理了类似的问题。此解决方案应该可以帮助您：

在自定义 UITabBarController 中抑制 moreNavigationController