从UIVIewController访问UITabBarController [英] Accessing UITabBarController from UIVIewController

问题描述

我正在开发一个基于UITabbar和视图层次结构的应用程序，如下所示。

I am developing an application based on UITabbar and the view hierarchy as follows.

UITabBarController ----> UINavigationController ----> UIViewController

UITabBarController ----> UINavigationController ----> UIViewController

我需要从UIIVewController访问UITabBarController。但是以下属性总是返回nil。

I need to access the UITabBarController from the UIIVewController . But following properties always returns nil.

self.tabBarController和self.navigationController.tabBarController

self.tabBarController and self.navigationController.tabBarController

有没有办法直接从子viewController访问Tabbarcontroller而不使用AppDelegate？

Is there a way to access the Tabbarcontroller directly from a child viewController without using the AppDelegate ?

@implementation HomeViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
        self.title = @"Home";
        self.navigationItem.title = @"Home";

        self.tabBarItem.image = [UIImage imageNamed:@"TabBarHome"];

        UITabBarController *tab = self.tabBarController;
         UITabBarController *tab1 = self.navigationController.tabBarController;
        UITabBarController *tab2 = self.navigationController.presentingViewController;



    }
    return self;
}

推荐答案

随着你的层次结构使用：

With the hierachy that you are using:

我可以从 ViewController 中轻松访问 UITabBarController ：

I can acces without problem the UITabBarController from the ViewController with:

self.tabBarController

self.tabBarController

移动你的自定义初始化为 viewDidLoad 或 viewDidAppear

Move your Custom initialization to viewDidLoad or viewDidAppear

然后为舒尔您可以使用 self.tabBarController访问 TabBarController

Then for shure you can access TabBarController with self.tabBarController

另一个到达你的TabBarController的方法是：

Another way to arrive to your TabBarController is:

UITabBarController *tabBarController = (UITabBarController *)[[[UIApplication sharedApplication] delegate] window].rootViewController;

但在你的情况下完全没必要。

But it is totally unnecessary in your case.

编辑：

如果您正在使用Xib，那么您已经在AppDelegate中以编程方式创建了一个TabBarController。我相信你有类似的东西：

If you are working with Xib, then you has been created a TabBarController programmatically in your AppDelegate. I'm sure you have something like:

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

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

然后你可以在你的ViewController中调用它：

Then you can call it in your ViewController:

AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]
UITabBarController *tabBarController = appdelegate.tabBarController;

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