title: Tab Bar Controller Delegate method does not gets called each time I tap on tab bar item
body: <p>I've tried with Tab Bar Controller delegate method </p>
  
  <pre><code>- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
  </code></pre>
  
  <p>implementing in a view controller and it works accordingly for the first time after launch. But when I switch to another tab item and coming back again to that specific tab item where I implemented the delegate, the delegae method does not gets called. </p>
  
  <p>Why is it happening ? it suppose to call each time I tap on tab item right ? Am I doing anything wrong or what would be the proper way to do it.</p>