如何在视图控制器之间进行转换并从每个控制器返回到主视图 con.？

Question

I have a MainViewController with a table view. When I click on a cell, the ChartViewController opens. It has a Back button to return to the MainViewController and a button to go to the SummaryViewController. The SummaryViewController button has a button to go to the ChartViewController and a Back button, but it also goes back to the ChartViewController. How do I return to the MainViewController using the Back button?

Transition code from Chart View Controller to SummaryViewController:

@IBAction func onSummaryButtonTapped(_ sender: Any) {
        let storyboard = UIStoryboard(name: "Main", bundle: .main)
        if let viewController = storyboard.instantiateViewController(withIdentifier: "StockSummaryViewController") as? StockSummaryViewController {
         navigationController?.pushViewController(viewController, animated: false)
        }
    }

Answer 1

add in ChartViewController when you create SummaryViewController

... summaryViewController.delegate = self

in SummaryViewController add a variable

weak var delegate: SummaryViewControllerDelegate?

and when user click "backButton" in SummaryViewController add

{
 ...
delegate?.backClick()
}

in ChartViewController add

extension ChartViewController: SummaryViewControllerDelegate {
   func backClick() {
      self.dismiss(animation: true, completion: nil)
    //or 
//self.popViewController(animation: true)

   }
}

and finally define anywhere

protocol SummaryViewControllerDelegate: class {\
   func backClick()
}