试试这个。

self.navigationItem.leftBarButtonItem?.target = "methodname"
func methodname ( ) {            
  //    enter code here
}

这个也试试。

override func viewWillAppear(animated: Bool) {
  //empty your array
}

将按钮替换为另一个答案中建议的自定义按钮可能不是一个好主意，因为您将失去默认的行为和样式。

另一个选择是在视图控制器上实现viewWillDisappear方法，并检查名为isMovingFromParentViewController的属性。如果那个属性为真，它意味着视图控制器正在消失，因为它正在被移除(弹出)。

应该是这样的:

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    if self.isMovingFromParentViewController {
        // Your code...
    }
}

在swift 4.2中

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    if self.isMovingFromParent {
        // Your code...
    }
}

你可以简单地从堆栈中删除不必要的控制器，就像这样:

self.navigationController?.viewControllers.removeAll(where: {
        $0 is FirstViewController || $0 is SecondWithPinController
    })

    override public func viewDidLoad() {
         super.viewDidLoad()
         self.navigationController?.navigationBar.topItem?.title = GlobalVariables.selectedMainIconName
         let image = UIImage(named: "back-btn")

         image = image?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal)

        self.navigationItem.leftBarButtonItem = UIBarButtonItem(image: image, style: UIBarButtonItemStyle.Plain, target: self, action: #selector(Current[enter image description here][1]ViewController.back) )
    }

    func back() {
      self.navigationController?.popToViewController( self.navigationController!.viewControllers[ self.navigationController!.viewControllers.count - 2 ], animated: true)
    }

在离开电流控制器之前，我需要显示警报。所以我是这样做的:

添加扩展UINavigationController与UINavigationBarDelegate 添加选择器到你的控制器导航

它的工作)

extension UINavigationController: UINavigationBarDelegate {
    public func navigationBar(_ navigationBar: UINavigationBar, shouldPop item: UINavigationItem) -> Bool {
        if let items = navigationBar.items, viewControllers.count < items.count {
            return true
        }

        let clientInfoVC = topViewController as? ClientInfoVC
        if clientInfoVC?.responds(to: #selector(clientInfoVC?.navigationShouldPopOnBack)) ?? false {
            clientInfoVC?.navigationShouldPopOnBack(completion: { isAllowPop in
                if isAllowPop {
                    DispatchQueue.main.async {
                        self.popViewController(animated: true)
                    }
                }
            })
        }

        DispatchQueue.main.async {
            self.popViewController(animated: true)
        }

        return false
    }
}

@objc func navigationShouldPopOnBack(completion: @escaping (Bool) -> ()) {
        let ok = UIAlertAction(title: R.string.alert.actionOk(), style: .default) { _ in
            completion(true)
        }
        let cancel = UIAlertAction(title: R.string.alert.actionCancel(), style: .cancel) { _ in
            completion(false)
        }
        let alertController = UIAlertController(title: "", message: R.string.alert.contractMessage(), preferredStyle: .alert)
        alertController.addAction(ok)
        alertController.addAction(cancel)
        present(alertController, animated: true, completion: nil)
    }

override func willMove(toParent parent: UIViewController?)
{
    super.willMove(toParent: parent)
    if parent == nil
    {
        print("This VC is 'will' be popped. i.e. the back button was pressed.")
    }
}