Show tab bar after its hidden

Question

Hi folks,

Is there any way to show a tab bar after it has been hidden? Got a tabbar-nav structure. For one of the tabs, I need to hide the tab bar for its 2nd and 3rd level view. But at the same time I will need to show its 1st and 4th view.

The sample code from Elements isn't really applicable here I think.

Any help is greatly appreciated.

Answer 1

you need to implement delegate method

- (BOOL)tabBarController:(UITabBarController *)tabBarController2 shouldSelectViewController:(UIViewController *)viewController

inside that you can check which index is selected and show the tabbar

if([tabBarController.viewControllers objectAtIndex:0] isEqual:viewController])// it is first tab
{
      tabBarControllertabBar.hidden = FALSE;
}

Answer 2

The UIViewControllers that are pushed onto the navigation stack can do the something like the following:

- (void)viewWillAppear:(BOOL)animated {
    self.tabBarController.tabBar.hidden = NO; // Or YES as desired.
}

EDIT: Added additional code below to deal with the frame. Don't think I particular recommend this idea since it relies on the internal default view structure of a UITabBarController.

Define the following category on UITabBarController:

@interface UITabBarController (Extras)
- (void)showTabBar:(BOOL)show;
@end

@implementation UITabBarController (Extras)
- (void)showTabBar:(BOOL)show {
    UITabBar* tabBar = self.tabBar;
    if (show != tabBar.hidden)
        return;
    // This relies on the fact that the content view is the first subview
    // in a UITabBarController's normal view, and so is fragile in the face
    // of updates to UIKit.
    UIView* subview = [self.view.subviews objectAtIndex:0];
    CGRect frame = subview.frame;
    if (show) {
        frame.size.height -= tabBar.frame.size.height;
    } else {
        frame.size.height += tabBar.frame.size.height;
    }
    subview.frame = frame;
    tabBar.hidden = !show;
}
@end

Then, instead of using the tabBar.hidden change I originally suggested, do the following:

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self.tabBarController showTabBar:NO];
}

Obviously making sure that the implementation has included the category definition so that 'showTabBar' is known.