ios - (Swift) 弹回导航 Controller

Question

我将描述我想做什么。我有 3 个 View Controller 。第一个应该是导航，我认为我在代码中犯了错误。
第一个 VC 通向第二个，第二个 VC 通向第三个 VC。第三个有一个按钮，应该返回第一个。

这就是我从 firstVC 中呈现 secondVC 的方式:

let mainStoryboard = UIStoryboard(name: "Main", bundle: Bundle.main)
let secondVC = (mainStoryboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController)   
presentVC(SecondVC)

func presentVC(_ VC: UIViewController) {
        let navController = UINavigationController(rootViewController: VC)
        navController.modalPresentationStyle = .fullScreen
        self.navigationController?.present(navController, animated: true, completion: nil)
    }

现在在第二个VC，当我点击 Close在右侧的 navBarItem 中，应该打开 thirdVC 并且它工作正常，这里是代码:

在 ViewDidLoad :

 self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Close", style: .plain, target: self, action:
#selector(closeSecondVC))

之后:

  @objc
    func closeSecondVC() {
    let mainStoryboard = UIStoryboard(name: "Main", bundle: Bundle.main)
            let thirdVC = (mainStoryboard.instantiateViewController(withIdentifier: "ThirdViewController") as! ThirdViewController)
            presentVC(thirdVC) //Same function as above.
}

而在第三个VC中的这个buttonClick上，我需要返回到firstVC，这就是我迷失的地方:

 @IBAction func btnTapped(_ sender: Any) {
        if let navController = self.navigationController {
            navController.popViewController(animated: true)
        }  //nothing happens on click
    }

Answer 1

在 btnTapped 中使用以下代码:

    for controller in self.navigationController!.viewControllers as Array 
    {
      // here YourViewController is your firstVC      
     if controller.isKind(of: YourViewController.self) {
            self.navigationController!.popToViewController(controller, animated: true)
            break
        }
    }

并且不要展示你的观点，插入你的观点流行。