ios 从 UIVIewController 访问 UITabBarController
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Accessing UITabBarController from UIVIewController
提问by rustylepord
I am developing an application based on UITabbar and the view hierarchy as follows.
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。
UITabBarController ----> UINavigationController ----> UIViewController
UITabBarController ----> UINavigationController ----> UIViewController
I need to access the UITabBarController from the UIIVewController . But following properties always returns nil.
我需要从 UIIVewController 访问 UITabBarController 。但是以下属性总是返回 nil。
self.tabBarController and self.navigationController.tabBarController
self.tabBarController 和 self.navigationController.tabBarController
Is there a way to access the Tabbarcontroller directly from a child viewController without using the AppDelegate ?
有没有办法直接从子 viewController 访问 Tabbarcontroller 而不使用 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;
}
回答by Gabriel.Massana
With the hierachy that you are using:
使用您正在使用的层次结构：
I can acces without problem the UITabBarControllerfrom the ViewControllerwith:
我可以毫无问题的存取权限UITabBarController从ViewController具有：
self.tabBarController
self.tabBarController
Move your Custom initialization to viewDidLoador viewDidAppear
将您的自定义初始化移动到viewDidLoad或viewDidAppear
Then for shure you can access TabBarControllerwith self.tabBarController
那么对于舒尔，您可以访问TabBarController与self.tabBarController
Another way to arrive to your TabBarController is:
到达 TabBarController 的另一种方法是：
UITabBarController *tabBarController = (UITabBarController *)[[[UIApplication sharedApplication] delegate] window].rootViewController;
But it is totally unnecessary in your case.
但在你的情况下完全没有必要。
EDIT:
编辑：
If you are working with Xib, then you has been created a TabBarController programmatically in your AppDelegate. I'm sure you have something like:
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。我相信你有这样的事情：
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController = [[UITabBarController alloc] init];
Then you can call it in your ViewController:
然后你可以在你的 ViewController 中调用它：
AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]
UITabBarController *tabBarController = appdelegate.tabBarController;
回答by Rashad
You are doing it wrong.
你做错了。
I've an app same as yours. I can access tabbar from viewDidLoad.
我有一个和你一样的应用程序。我可以从viewDidLoad.
Try this:
尝试这个：
- (void)viewDidLoad {
[super viewDidLoad];
[self.tabBarController setSelectedIndex:1];
}
Hope this helps.. :)
希望这可以帮助.. ：）
