这是我自己解决问题的方法

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    self.navigationItem.leftBarButtonItem?.action = #selector(self.back(sender:))
    self.navigationItem.leftBarButtonItem?.target = self
}

@objc func back(sender: UIBarButtonItem) {

}

据我所知，你想清空你的数组，当你按下后退按钮，弹出到你之前的ViewController，让你的数组加载在这个屏幕上

let settingArray  = NSMutableArray()
@IBAction func Back(sender: AnyObject) {
    self. settingArray.removeAllObjects()
    self.dismissViewControllerAnimated(true, completion: nil)
} 

我通过以下方法做到了这一点:

斯威夫特3

override func didMoveToParentViewController(parent: UIViewController?) {
   super.didMoveToParentViewController(parent)

   if parent == nil {
      println("Back Button pressed.")
      delegate?.goingBack()
   }           
}

斯威夫特4

override func didMove(toParent parent: UIViewController?) {
    super.didMove(toParent: parent)

    if parent == nil {
        debugPrint("Back Button pressed.")
    }
}

不需要自定义后退按钮。

对于Swift 5，我们可以检查它在视图中是否会消失

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

    if self.isMovingFromParent {
        delegate?.passValue(clickedImage: selectedImage)
    }
}

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
    })

Swift 5 __ Xcode 11.5

在我的情况下，我想做一个动画，当它完成后，返回。 一种覆盖后退按钮默认动作的方法 调用你的自定义动作是这样的:

     override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        setBtnBack()
    }

    private func setBtnBack() {
        for vw in navigationController?.navigationBar.subviews ?? [] where "\(vw.classForCoder)" == "_UINavigationBarContentView" {
            print("\(vw.classForCoder)")
            for subVw in vw.subviews where "\(subVw.classForCoder)" == "_UIButtonBarButton" {
                let ctrl = subVw as! UIControl
                ctrl.removeTarget(ctrl.allTargets.first, action: nil, for: .allEvents)
                ctrl.addTarget(self, action: #selector(backBarBtnAction), for: .touchUpInside)
            }
        }
    }


    @objc func backBarBtnAction() {
        doSomethingBeforeBack { [weak self](isEndedOk) in
            if isEndedOk {
                self?.navigationController?.popViewController(animated: true)
            }
        }
    }


    private func doSomethingBeforeBack(completion: @escaping (_ isEndedOk:Bool)->Void ) {
        UIView.animate(withDuration: 0.25, animations: { [weak self] in
            self?.vwTxt.alpha = 0
        }) { (isEnded) in
            completion(isEnded)
        }
    }

或者你可以使用这个方法一次来探索NavigationBar视图层次结构，并获得访问_UIButtonBarButton视图的索引，转换为UIControl，删除目标-动作，并添加你的自定义目标-动作:

    private func debug_printSubviews(arrSubviews:[UIView]?, level:Int) {
        for (i,subVw) in (arrSubviews ?? []).enumerated() {
            var str = ""
            for _ in 0...level {
                str += "\t"
            }
            str += String(format: "%2d %@",i, "\(subVw.classForCoder)")
            print(str)
            debug_printSubviews(arrSubviews: subVw.subviews, level: level + 1)
        }
    }

    // Set directly the indexs
    private func setBtnBack_method2() {
        // Remove or comment the print lines
        debug_printSubviews(arrSubviews: navigationController?.navigationBar.subviews, level: 0)   
        let ctrl = navigationController?.navigationBar.subviews[1].subviews[0] as! UIControl
        print("ctrl.allTargets: \(ctrl.allTargets)")
        ctrl.removeTarget(ctrl.allTargets.first, action: nil, for: .allEvents)
        print("ctrl.allTargets: \(ctrl.allTargets)")
        ctrl.addTarget(self, action: #selector(backBarBtnAction), for: .touchUpInside)
        print("ctrl.allTargets: \(ctrl.allTargets)")
    }