Call different viewControllers on click of tab bar of UITabBarController

Question

Below is the image of my UITabBarController structure in storyboard.

Right now in storyboard, AboutUsViewController(UIViewController) is bound with my tabBar button click event ie If I click on tabBar button, AboutUsViewController is opening but now my functionality is based on certain conditions. I want to call ContactRequstViewController instead of AboutUsViewController on same tabBar button click.

Following is my code to open ContactRequstViewController .

-(void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
      if (tabBarController.selectedIndex == 2){
           UIStoryboard *story =  [UIStoryboard storyboardWithName:@"iPhone" bundle:nil];
           ContactRequstViewController *contactVC = [story instantiateViewControllerWithIdentifier:@"ContactUsView"];
          [self.navigationController pushViewController:contactVC animated:YES];
      }
}

After writing above code I am not able to load ContactRequestViewController .

Answer 1

If you want to replace the root view controller at that selected tab based on custom logic, try using setViewControllers:animated: method of the UITabBarController .

You could do something like this:

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
    if (tabBarController.selectedIndex == 1 && tabBarController.viewControllers.count > tabBarController.selectedIndex) {
        BOOL shouldShowContactVC = (BOOL)(rand() % 2);
        NSMutableArray *viewControllers = [[tabBarController viewControllers] mutableCopy];
        UIStoryboard *main = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
        UIViewController *newVC = nil;
        if (shouldShowContactVC) {
            newVC = [main instantiateViewControllerWithIdentifier:@"ContactUsVC"];
        } else {
            newVC = [main instantiateViewControllerWithIdentifier:@"AboutUsVC"];
        }
        if (newVC) {
            [viewControllers replaceObjectAtIndex:tabBarController.selectedIndex withObject:newVC];
            newVC.tabBarItem = viewController.tabBarItem;
            [tabBarController setViewControllers:viewControllers animated:YES];
        }
    }
}

Answer 2

In my experience , sometimes we don't use tabbarVC, because it's not flexible, such as hide , show , or change items number . So we set a navigationVC as rootVC, u can create a View, just make it's look like a tabbarVC. This view is more easy to used.And u don't need to care any delegate method or something else. u can do anything u want. That's all.