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Why are my TabBar buttons disabled when I first load my view controller?

I have an iPhone app where I switch between two tabs. The problem is that in the view where I change the stripes of the tabs, my tab bar buttons are disabled only the first time the view is loaded (when loadView and viewDidLoad are called). In other words, if I switch to this view, the buttons on the tab bar are disabled. If I go to one of these views and then come back, the buttons will be turned on. Difference in view lifecycle calls:

Work - loadView viewDidLoad viewWillAppear viewDidAppear

Doesn't work - viewWillAppear viewDidAppear

Swap is in viewDidAppear right now. If I put swap in viewWillAppear, the buttons will work fine, but the view controller will jump down, because the tab strip switching animation is executed during the transition to viewing animation.

My first guess was that some view sits on top of the tab bar. I do not think this is true. I printed out the view hierarchies in both scenarios, and there is only one slight difference.

Here is the view hierarchy for the working scenario:

<UIWindow: 0x5a4c7c0; frame = (0 0; 320 480); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x5a4ca30>>
   | <UILayoutContainerView: 0x5a591b0; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x5a59230>>
   |    | <UITransitionView: 0x5a59c00; frame = (0 0; 320 480); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x5a59ca0>>
   |    |    | <UIViewControllerWrapperView: 0x5a6e960; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x5a6e9e0>>
   |    |    |    | <UILayoutContainerView: 0x5a5bb70; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x5a5bbc0>>
   |    |    |    |    | <UINavigationTransitionView: 0x5a5c290; frame = (0 0; 320 480); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x5a19400>>
   |    |    |    |    |    | <UIViewControllerWrapperView: 0xaf01810; frame = (0 20; 320 460); layer = <CALayer: 0xaf01840>>
   |    |    |    |    |    |    | <UIView: 0x5abcba0; frame = (0 0; 320 460); layer = <CALayer: 0x5a8ff50>>
   |    |    |    |    |    |    |    | <CaptureAuxMenu: 0x5ac6850; frame = (0 480; 320 49); layer = <CALayer: 0x5ac68e0>>
   |    |    |    |    |    |    |    |    | <UIImageView: 0x5ac6a50; frame = (0 0; 320 49); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5ac6a80>>
   |    |    |    |    |    |    |    |    | <UIButton: 0x5ac67c0; frame = (18 7; 80 31); opaque = NO; layer = <CALayer: 0x5ac6b80>>
   |    |    |    |    |    |    |    |    |    | <UIImageView: 0x5acf910; frame = (0 0; 80 31); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5acf940>>
   |    |    |    |    |    |    |    |    | <UIButton: 0x5ac7ed0; frame = (116 7; 80 31); opaque = NO; layer = <CALayer: 0x5ac7b50>>
   |    |    |    |    |    |    |    |    |    | <UIImageView: 0x5acf890; frame = (0 0; 80 31); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5acf8c0>>
   |    |    |    |    |    |    |    |    | <UIButton: 0x5ac91f0; frame = (285 10; 25 25); opaque = NO; layer = <CALayer: 0x5ac8e70>>
   |    |    |    |    |    |    |    |    |    | <UIImageView: 0x5acf810; frame = (0 0; 25 25); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5acf840>>

   |    | <UITabBar: 0x5a59560; frame = (0 431; 320 480); hidden = YES; autoresize = W+TM; layer = <CALayer: 0x5a59600>>
   |    |    | <UITabBarButton: 0x5a638f0; frame = (2 1; 60 479); opaque = NO; layer = <CALayer: 0x5a660a0>>
   |    |    |    | <UITabBarSelectionIndicatorView: 0x5a6e250; frame = (0 2; 60 475); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6e280>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a662a0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a66360>>
   |    |    |    | <UITabBarButtonLabel: 0x5a63ba0; frame = (16 465; 28 13); text = 'string'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a63990>>
   |    |    | <UITabBarButton: 0x5a660d0; frame = (66 1; 60 479); opaque = NO; layer = <CALayer: 0x5a674a0>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a663c0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a66410>>
   |    |    |    | <UITabBarButtonLabel: 0x5a66cc0; frame = (16 465; 28 13); text = 'string'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a665e0>>
   |    |    | <UITabBarButton: 0x5a65990; frame = (130 1; 60 479); opaque = NO; layer = <CALayer: 0x5a68140>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a689c0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a68170>>
   |    |    |    | <UITabBarButtonLabel: 0x5a696b0; frame = (16 465; 28 13); text = 'string'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a68ba0>>
   |    |    | <UITabBarButton: 0x5a68420; frame = (194 1; 60 479); opaque = NO; layer = <CALayer: 0x5a697d0>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a6abf0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6ac40>>
   |    |    |    | <UITabBarButtonLabel: 0x5a6af20; frame = (8 465; 44 13); text = 'FRIENDS'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a678c0>>
   |    |    | <UITabBarButton: 0x5a6a5a0; frame = (258 1; 60 479); opaque = NO; layer = <CALayer: 0x5a6b230>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a6b9b0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6b260>>
   |    |    |    | <UITabBarButtonLabel: 0x5a677c0; frame = (8 465; 44 13); text = 'PROFILE'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6b3d0>>
   |    | <UIImageView: 0x5a6b850; frame = (0 480; 320 49); opaque = NO; tag = 89364833; layer = <CALayer: 0x5a6d200>>
   |    |    | <UIButton: 0x5a6d580; frame = (0 0; 64 49); opaque = NO; layer = <CALayer: 0x5a6d660>>
   |    |    |    | <UIImageView: 0x5c35b20; frame = (0 0; 63 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35b50>>
   |    |    | <UIButton: 0x5a63480; frame = (64 0; 64 49); opaque = NO; tag = 1; layer = <CALayer: 0x5a66170>>
   |    |    |    | <UIImageView: 0x5c35aa0; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35ad0>>
   |    |    | <UIButton: 0x5a6da30; frame = (128 0; 64 49); opaque = NO; tag = 2; layer = <CALayer: 0x5a6dac0>>
   |    |    |    | <UIImageView: 0x5c35a20; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35a50>>
   |    |    | <UIButton: 0x5a6dc60; frame = (192 0; 64 49); opaque = NO; tag = 3; layer = <CALayer: 0x5a6dcf0>>
   |    |    |    | <UIImageView: 0x5c359a0; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c359d0>>
   |    |    | <UIButton: 0x5a6de90; frame = (256 0; 64 49); opaque = NO; tag = 4; layer = <CALayer: 0x5a6df20>>
   |    |    |    | <UIImageView: 0x5c358c0; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35970>>

Here is the view hierarchy for the failed scenario:

<UIWindow: 0x5a4c7c0; frame = (0 0; 320 480); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x5a4ca30>>
   | <UILayoutContainerView: 0x5a591b0; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x5a59230>>
   |    | <UITransitionView: 0x5a59c00; frame = (0 0; 320 480); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x5a59ca0>>
   |    |    | <UIViewControllerWrapperView: 0x5a6e960; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x5a6e9e0>>
   |    |    |    | <UILayoutContainerView: 0x5a5bb70; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x5a5bbc0>>
   |    |    |    |    | <UINavigationTransitionView: 0x5a5c290; frame = (0 0; 320 480); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x5a19400>>
   |    |    |    |    |    | <UIViewControllerWrapperView: 0x5ae49f0; frame = (0 20; 320 411); layer = <CALayer: 0x5ae4870>>
   |    |    |    |    |    |    | <UIView: 0x5abcba0; frame = (0 0; 320 411); layer = <CALayer: 0x5a8ff50>>
   |    |    |    |    |    |    |    | <CaptureAuxMenu: 0x5ac6850; frame = (0 480; 320 49); layer = <CALayer: 0x5ac68e0>>
   |    |    |    |    |    |    |    |    | <UIImageView: 0x5ac6a50; frame = (0 0; 320 49); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5ac6a80>>
   |    |    |    |    |    |    |    |    | <UIButton: 0x5ac67c0; frame = (18 7; 80 31); opaque = NO; layer = <CALayer: 0x5ac6b80>>
   |    |    |    |    |    |    |    |    |    | <UIImageView: 0x5acf910; frame = (0 0; 80 31); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5acf940>>
   |    |    |    |    |    |    |    |    | <UIButton: 0x5ac7ed0; frame = (116 7; 80 31); opaque = NO; layer = <CALayer: 0x5ac7b50>>
   |    |    |    |    |    |    |    |    |    | <UIImageView: 0x5acf890; frame = (0 0; 80 31); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5acf8c0>>
   |    |    |    |    |    |    |    |    | <UIButton: 0x5ac91f0; frame = (285 10; 25 25); opaque = NO; layer = <CALayer: 0x5ac8e70>>
   |    |    |    |    |    |    |    |    |    | <UIImageView: 0x5acf810; frame = (0 0; 25 25); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5acf840>>

   |    | <UITabBar: 0x5a59560; frame = (0 431; 320 480); hidden = YES; autoresize = W+TM; layer = <CALayer: 0x5a59600>>
   |    |    | <UITabBarButton: 0x5a638f0; frame = (2 1; 60 479); opaque = NO; layer = <CALayer: 0x5a660a0>>
   |    |    |    | <UITabBarSelectionIndicatorView: 0x5a6e250; frame = (0 2; 60 475); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6e280>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a662a0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a66360>>
   |    |    |    | <UITabBarButtonLabel: 0x5a63ba0; frame = (16 465; 28 13); text = 'string'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a63990>>
   |    |    | <UITabBarButton: 0x5a660d0; frame = (66 1; 60 479); opaque = NO; layer = <CALayer: 0x5a674a0>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a663c0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a66410>>
   |    |    |    | <UITabBarButtonLabel: 0x5a66cc0; frame = (16 465; 28 13); text = 'string'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a665e0>>
   |    |    | <UITabBarButton: 0x5a65990; frame = (130 1; 60 479); opaque = NO; layer = <CALayer: 0x5a68140>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a689c0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a68170>>
   |    |    |    | <UITabBarButtonLabel: 0x5a696b0; frame = (16 465; 28 13); text = 'string'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a68ba0>>
   |    |    | <UITabBarButton: 0x5a68420; frame = (194 1; 60 479); opaque = NO; layer = <CALayer: 0x5a697d0>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a6abf0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6ac40>>
   |    |    |    | <UITabBarButtonLabel: 0x5a6af20; frame = (8 465; 44 13); text = 'FRIENDS'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a678c0>>
   |    |    | <UITabBarButton: 0x5a6a5a0; frame = (258 1; 60 479); opaque = NO; layer = <CALayer: 0x5a6b230>>
   |    |    |    | <UITabBarSwappableImageView: 0x5a6b9b0; frame = (6 218; 48 32); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6b260>>
   |    |    |    | <UITabBarButtonLabel: 0x5a677c0; frame = (8 465; 44 13); text = 'PROFILE'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5a6b3d0>>
   |    | <UIImageView: 0x5a6b850; frame = (0 480; 320 49); opaque = NO; tag = 89364833; layer = <CALayer: 0x5a6d200>>
   |    |    | <UIButton: 0x5a6d580; frame = (0 0; 64 49); opaque = NO; layer = <CALayer: 0x5a6d660>>
   |    |    |    | <UIImageView: 0x5c35b20; frame = (0 0; 63 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35b50>>
   |    |    | <UIButton: 0x5a63480; frame = (64 0; 64 49); opaque = NO; tag = 1; layer = <CALayer: 0x5a66170>>
   |    |    |    | <UIImageView: 0x5c35aa0; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35ad0>>
   |    |    | <UIButton: 0x5a6da30; frame = (128 0; 64 49); opaque = NO; tag = 2; layer = <CALayer: 0x5a6dac0>>
   |    |    |    | <UIImageView: 0x5c35a20; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35a50>>
   |    |    | <UIButton: 0x5a6dc60; frame = (192 0; 64 49); opaque = NO; tag = 3; layer = <CALayer: 0x5a6dcf0>>
   |    |    |    | <UIImageView: 0x5c359a0; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c359d0>>
   |    |    | <UIButton: 0x5a6de90; frame = (256 0; 64 49); opaque = NO; tag = 4; layer = <CALayer: 0x5a6df20>>
   |    |    |    | <UIImageView: 0x5c358c0; frame = (0 0; 64 49); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x5c35970>>

, , - 7 8 . , UIViewControllerWrapperView UIView , , , , UIView , - UIViewControllerWrapperView.

:

- (void)viewDidAppear:(BOOL)animated{ 
    [super viewDidAppear:animated];
    [AppHelpers hideTabBarController:self.tabBarController withHidden:YES];
    [self showCaptureTabBar];
}

+ (void) hideTabBarController:(UITabBarController *)tbc withHidden:(BOOL)hide {

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];

    for(UIView *view in tbc.view.subviews)
    {       
        if([view isKindOfClass:[UIImageView class]])
        {
            if (hide) {
                [view setFrame:CGRectMake(view.frame.origin.x, 480, view.frame.size.width, view.frame.size.height)];
            } else {
                [view setFrame:CGRectMake(view.frame.origin.x, 431, view.frame.size.width, view.frame.size.height)];
            }
        }else {
            if (hide) {
                // When hiding the tabbarcontroller, the view should be full height
                [view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 480)];
            } else {
                // When showing the tabbarcontroller, the view needs to leave 49px of room for it at the bottom
                [view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 431)];
            }
        }
    }

    [UIView commitAnimations];  
}

- (void)showCaptureTabBar {
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:1];
    [captureTabBar setFrame:CGRectMake(captureTabBar.frame.origin.x, 412.0f, captureTabBar.frame.size.width, captureTabBar.frame.size.height)];
    [UIView commitAnimations];
}

, , .

+3
2

, . , , . UIViews , , .

, , " " "" , . , , .

+3

/ beginAnimations/endAnimations?

- (void)viewDidAppear:(BOOL)animated{ 
 [super viewDidAppear:animated];

 [UIView beginAnimations:@"firstAnimation" context:NULL];
 [UIView setAnimationDuration:0.3];
 [AppHelpers hideTabBarController:self.tabBarController withHidden:YES];

 [UIView beginAnimations:@"secondAnimation" context:NULL];
 [UIView setAnimationDuration:1.0];
 [self showCaptureTabBar];

 [UIView commitAnimations];
 [UIView commitAnimations];

}

? , ...

...

:

, , / , hidden?

        if (hide) {
            view.hide = YES;
        } else {
            view.hide = NO;
        }

, , - ( , ) : viewWillAppear, hideTabBarController showCaptureTabBar; 0 ( , hideTabBarController, , , showCaptureTabBar):

[AppHelpers hideTabBarController:self.tabBarController withHidden:YES];
[self performSelector:@selector(showCaptureTabBar) withObject:nil afterDelay:0];

, hideTabBarController 0,3 , 0,3, , .

0

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