UINavigationController在顶部存在差距

Question

我通过代码添加了一个UINavigationController，但它在顶部留下了差距..大约20 px ..

如果我切换到其他标签然后返回此标签，它就会消失，但在NavBar移动到正确位置之前大约0.2秒可以看到它。

我已经搜索过StackOverflow但我找不到解决方案......

这是我的代码的一部分：

appDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    .....
    UIViewController *vc1 = [[Tab1 alloc] initWithNibName:@"Tab1" bundle:nil];
    UIViewController *vc2 = [[FreshEpisodeController alloc] initWithNibName:@"FreshEpisodeController" bundle:nil];
    UIViewController *vc3 = [[Tab3 alloc] initWithNibName:@"Tab3" bundle:nil];
    UIViewController *vc5 = [[DownloadListController alloc] initWithNibName:@"DownloadListController" bundle:nil];
    self.tabBarController = [[UITabHost alloc] init];
    self.tabBarController.viewControllers = [NSArray arrayWithObjects:vc2, vc1, vc3, vc5, nil];
    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    .....
}

Tab3.m

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        [[self view] addSubview:mNavController.view];
        self.title = NSLocalizedString(@"Collection List", @"Collection List");
        self.tabBarItem.image = [UIImage imageNamed:@"tab3"];
    }
    return self;
}

Tab3.xib中的

，我有UIView和UINavigationController（mNavController）

如果我将Tab3设置为第一次显示（我把它放在第一个标签页），那么差距不存在 但是，如果我把它放到第二个标签，它显示我是否切换到查看Tab3。

Answer 1

在 ViewController 的属性部分中将置顶栏属性设置为取消选中可能会有所帮助。

Answer 2

为视图控制器将“wantsFullScreenLayout”属性设置为“YES”

Answer 3

尝试这样做

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        [[self view] addSubview:mNavController.view];
        mNavController.view.frame = self.view.bounds; //here you assign the subView frame to fit superView area
        self.title = NSLocalizedString(@"Collection List", @"Collection List");
        self.tabBarItem.image = [UIImage imageNamed:@"tab3"];
    }
    return self;
}

Answer 4

在UINavigationController (mNavController)方法中添加viewDidLoad，代码应如下所示：

- (void)viewDidLoad {
    [super viewDidLoad];

    [[self view] addSubview:mNavController.view];
    self.title = NSLocalizedString(@"Collection List", @"Collection List");
    self.tabBarItem.image = [UIImage imageNamed:@"tab3"];
}

现在享受.....