self.navigationController.tabBarController.selectedIndex not working

Question

I have a UITabBarController which containing 4 different UIViewControllers.

On first tab there is a UINavigationViewController

Answer 1

Do the following, before trying to change tab:

UITabBarController *tab=self.tabBarController;

if (tab){
   NSLog(@"I have a tab bar");
   [self.tabBarController setSelectedIndex:1];
}
else{
   NSLog(@"I don't have");
}