title: How to navigate to some other View Controller when Navigation Controller back button is pressed?
body: <p>I have a <code>viewController</code> in which, on the click of back button, I need to go to a specific <code>viewController</code> and call its method.So I created a <code>barButton</code> and added as a <code>BACK</code> button in navigation bar.When its <code>selector</code> is called I can see only see a black screen, nothing else.</p>
  
  <p>Here how I am doing it.</p>
  
  <p>In <code>viewDidLoad</code></p>
  
  <pre><code>  //Back Button in navigation Bar.
  UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:self action:@selector(navigationBackButtonClicked:)];
  self.navigationItem.leftBarButtonItem=newBackButton;
  </code></pre>
  
  <p>The <code>selector</code> below executes and shows a black screen. </p>
  
  <pre><code>  -(void)navigationBackButtonClicked:(UIBarButtonItem *)sender {
     SharedManager *sharedManagerObject = [SharedManager sharedInstance];
  
     NSString *source = sharedManagerObject.toCityString;
     NSString *destination =  sharedManagerObject.fromCityString;
     NSString *dateStr = sharedManagerObject.dateSelected_String;
  
     BusListViewController *buslist_VC = [self.storyboard instantiateViewControllerWithIdentifier:@"BusListViewController"];
  
  
     [buslist_VC getBusListForSource:source destination:destination date:dateStr];
  
     [self.navigationController popToViewController:buslist_VC animated:YES];
  
   }
  </code></pre>