Navigation bar not showing iOS swift

Question

I am having multiple view controller in my application. I want to hide navigationbar in my first view controller. So I use the following code to hide the navigation bar

navigationController?.setNavigationBarHidden(navigationController?.navigationBarHidden == false, animated: true); 

Now I want to add navigation bar in some other viewController but, my navigation bar not visible in that viewcontroller. Why it is happening?

My storyboard showing the navigation bar but once I try to run my application it is gone.

If I hide navigation bar from one view controller then we can't use navigation controller, Is it so? I hope I am wrong. Then what are the reasons for navigation bar not shown?

EDIT:

Also I want my view controller in portrait mode only. So I did the following Is that causing the issue?

extension UINavigationController{     public override func shouldAutorotate() -> Bool {         if (UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeLeft ||             UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeRight ||             UIDevice.currentDevice().orientation == UIDeviceOrientation.Unknown) {                 return false         }         else {             return true         }     }          public override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {         return [UIInterfaceOrientationMask.Portrait ,UIInterfaceOrientationMask.PortraitUpsideDown]     }       } 

Edit 1:

I am using following code to move from one view controller not link from the storyboard. Is that causing issue now?

 let storyboard = UIStoryboard(name: "Main", bundle: nil)         let secondViewController = storyboard.instantiateViewControllerWithIdentifier("HomeVC")         presentViewController(secondViewController, animated: false, completion: nil) 

Edit 2:

Please check my following screenshots. Which are my settings for secondview controller

Edit 3:

Here is my navigation controller attribute inspector

Answer 1

Navigation Controller is a controller, which has stack of view controllers. So if you have something like this:

NAV -> A -> (segue) B

Even if you'll hide navigation bar you still should be able to make segues. Also can't you just unhide navigation bar in second (B) view controller in viewWillAppear? And in first the same way hide it on viewWillAppear.

edit: Final solution to the problem: Use:

 let controller = storyboard.instantiateViewControllerWithIdentifier("HomeVC")  self.navigationController!.pushViewController(controller)  

instead of:

let secondViewController = storyboard.instantiateViewControllerWithIdentifier("HomeVC") presentViewController(secondViewController, animated: false, completion: nil) 

Because pushViewController will add secondViewController to its stack. presentViewController was replacing your navigation controller that's why you couldn't see navigation bar.