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iOS

Posted by PETRA LUTZ
PETRA LUTZ
2,922 Points

TabBar and NavigationBar got hiden after adding pushViewController

I want to pass the variable " uid " between the FirstViewController and SecondViewController, so I used the following code to pass it. It successfully pass it, but the problem it hides the NavigationBar and the TabBar !

Any ideas on how I can solve it ?

  SecondViewController *vc2 = [self.storyboard instantiateViewControllerWithIdentifier:@"SecondViewController"];
     vc2.uid = uid;
     [self.navigationController pushViewController:vc2  animated:YES];

9 Answers

Thomas Nilsen
Thomas Nilsen
14,957 Points
Thomas Nilsen
Thomas Nilsen
14,957 Points

Try something like this:

    UINavigationController *navigationController = [self.storyboard instantiateViewControllerWithIdentifier:@"SecondViewController"];

    SecondViewController * vc2 = (SecondViewController *)navigationController.topViewController;
    vc2.uid = uid;

    [self.navigationController pushViewController:vc2  animated:YES];
PETRA LUTZ
PETRA LUTZ
2,922 Points

What is topViewController ?

PETRA LUTZ
PETRA LUTZ
2,922 Points
PETRA LUTZ
PETRA LUTZ
2,922 Points

The app crashes and says : 

     [SecondViewController topViewController]: unrecognized selector sent to instance 0x1f223250
Thomas Nilsen
Thomas Nilsen
14,957 Points
Thomas Nilsen
Thomas Nilsen
14,957 Points

topViewController is the viewController that is visible in the navigation stack. Your storyboard might look a bit different than what I first thought. Would you mind taking a screenshot of the storyboard?

PETRA LUTZ
PETRA LUTZ
2,922 Points

Here is it : http://s29.postimg.org/afhfg3lp3/nin.png

Thomas Nilsen
Thomas Nilsen
14,957 Points
Thomas Nilsen
Thomas Nilsen
14,957 Points

hmm - I don't see any reason why you navigationBar will disappear. Try adding this in SecondViewController:

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated]; 
    [self.navigationController setNavigationBarHidden:NO animated:animated];
}
PETRA LUTZ
PETRA LUTZ
2,922 Points

Still, the same issue. In my case I am passing from LoginViewController (UIViewController) to FirstViewController(UITabBarController) [Please see picture again]. I think there is a problem of communication between these two.

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

if you are using storyboards why not use a segue and implement prepare for segue to pass the variable?

PETRA LUTZ
PETRA LUTZ
2,922 Points
PETRA LUTZ
PETRA LUTZ
2,922 Points

I tried to do that, but in that case the uid is not passed.

PETRA LUTZ
PETRA LUTZ
2,922 Points
PETRA LUTZ
PETRA LUTZ
2,922 Points

I tried to do that, but in that case the uid is not passed.

Stone Preston
Stone Preston
42,016 Points

can you show me what you used? also is the viewcontroller you are trying to pass the variable to embedded in a navigation controller?

PETRA LUTZ
PETRA LUTZ
2,922 Points
PETRA LUTZ
PETRA LUTZ
2,922 Points

I used this :

    -(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
      {
      if ([segue.identifier isEqualToString:@"seg"]) {
      FirstViewController *vc2 = [segue destinationViewController];
      vc2.uid = uid;
      }
      }

The FirstViewController is a login screen with, 2 fields (email, password) after receiving the success login from my jSON file, it gives success, with the uid the idea here is that I want to pass this uid inside the app to use it in other tab, so that It shows the content depending on the uid. The viewcontroller is embedded in a navigation controller.

Thomas Nilsen
Thomas Nilsen
14,957 Points
Thomas Nilsen
Thomas Nilsen
14,957 Points

if it's embedded in a navigation controller do this:

-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"seg"]) {
        UINavigationController *navigationController = segue.destinationViewController;
        FirstViewController *vc2 = (FirstViewController *)navigationController.topViewController;
        vc2.uid = uid;
    }
}