title: Navigation Bar Back Button not working
body: <p>I am trying add a custom back button so that I can perform some tasks before popping the controller. But no matter how hard I tried this function bind with back button doesn't work. I am adding some code to understand</p>
  
  <pre><code>-(void)customizeNavigationBar
  {
      self.navigationController.navigationBarHidden = NO;
      self.navigationItem.title = @"Video Call";
  
     UIBarButtonItem *backButton = [[UIBarButtonItem alloc] 
                initWithTitle:@" " style:UIBarButtonItemStylePlain 
                target:self action:@selector(didBackBtnTap)];
     [self.navigationItem setBackBarButtonItem:backButton];
  }
  </code></pre>
  
  <p>and this is the function, which is not calling at all,</p>
  
  <pre><code>-(void)didBackBtnTap
  {
      [self popToProfileScreen];
  }
  </code></pre>
  
  <p>Please suggest any solution, Thanks in advance.</p>