Switch between different Views in SWIFT

Question

I read a lot of questions / answers in the stack overflow community about switching between different ViewControllers but I couldn't find the correct answer for my specific problem.

1. I'm using a NavigationViewController to "connect" all my different viewControllers (ViewController / TableViewController / CollectionViewController)

2. I have got some classes which aren't depending on a ViewController class. For example to to calculate anything in my "calculate" class.

I'm searching for an easy solution, to switch between all my ViewControllers. And I would like to decide in my "calculate" class e.g. to go one step back in my Navigation ViewController.

In the moment I use this:

1. Example to switch between two different ViewControllers:

   let sb = UIStoryboard(name: "Main", bundle: nil)
   let vc = sb.instantiateViewControllerWithIdentifier("StartPage") as! StartPageView
   self.presentViewController(vc, animated: true, completion: nil)
   

PROBLEM: This example only works in a ViewController class and the navigation bar disappears.

2. Example to go one step back in my NavigationViewController:

   self.navigationController?.popViewControllerAnimated(true)
   

PROBLEM: This example only works in a ViewController class.

EDIT 1:

I found a nice solution to call all my viewControllers with this part of code:

    let switchViewController = self.navigationController?.viewControllers[1] as! ScanTableView
    self.navigationController?.popToViewController(switchViewController, animated: true)

How can I call this code in a non ViewController class?

Answer 1

Push the new view controller onto your existing navigation stack, rather than presenting it modally:

let vc = self.storyboard!.instantiateViewControllerWithIdentifier("StartPage") as! StartPageView
self.navigationController!.pushViewController(vc, animated: true)