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
    })

如果你正在使用navigationController，那么将UINavigationControllerDelegate协议添加到类中，并添加delegate方法，如下所示:

class ViewController:UINavigationControllerDelegate {

    func navigationController(navigationController: UINavigationController, willShowViewController viewController: UIViewController,
animated: Bool) {
        if viewController === self {
            // do here what you want
        }
    }
}

每当导航控制器滑到新屏幕时，就调用此方法。如果返回按钮被按下，新的视图控制器就是ViewController本身。

我的偏好是在导航控制器中覆盖popViewController。这样做的好处是:

你的应用程序保持默认的后退按钮外观和动画，你不需要管理它。如果用户在手机上设置了大号文本，这尤其有用，因为默认的后退按钮会根据用户的设置增加或减少大小。 你可以完全停止视图弹出，不像使用viewWillDisappear。

首先，创建一个自定义导航控制器类(并确保将其分配给故事板中的导航控制器或任何创建导航控制器的地方):

class NavControllerWithBackButtonOverride: UINavigationController {

    var backButtonOverride: (() -> Void)? = nil

    override func popViewController(animated: Bool) -> UIViewController? {

        if backButtonOverride != nil {
            //if anything is assigned to the backButtonOverride the override will run
            self.backButtonOverride!()
            return nil
        } else {
            //otherwise the default popViewController will run
            return super.popViewController(animated: animated)
        }
    }
}

然后通过给backButtonOverride变量赋值，在视图控制器中启用/禁用重载:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    self.enableCustomBackButton()
}

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

/**
 Custom Back Button
 */

func customBackButtonAction() {
    print("DO THIS INSTEAD")
}

func enableCustomBackButton() {
    if let nav = self.navigationController as? NavControllerWithBackButtonOverride {
        nav.backButtonOverride = { self.customBackButtonAction() }
        nav.interactivePopGestureRecognizer?.isEnabled = false
    }    
}

func disableCustomBackButton() {
    if let nav = self.navigationController as? NavControllerWithBackButtonOverride {
    nav.backButtonOverride = nil
    nav.interactivePopGestureRecognizer?.isEnabled = true
    }
}

注意:我还禁用了interactivePopGestureRecognizer，因为它会导致自定义设置的问题。

我通过调用/重写viewWillDisappear来实现这一点，然后像这样访问navigationController的堆栈:

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

    let stack = self.navigationController?.viewControllers.count

    if stack >= 2 {
        // for whatever reason, the last item on the stack is the TaskBuilderViewController (not self), so we only use -1 to access it
        if let lastitem = self.navigationController?.viewControllers[stack! - 1] as? theViewControllerYoureTryingToAccess {
            // hand over the data via public property or call a public method of theViewControllerYoureTryingToAccess, like
            lastitem.emptyArray()
            lastitem.value = 5
        }
    }
}

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) {

}

你可以子类化UINavigationController并重写popViewController(animated: Bool)。除了能够在那里执行一些代码，你还可以防止用户完全返回，例如提示保存或丢弃他当前的工作。

示例实现，其中您可以设置popHandler，由推送的控制器设置/清除。

class NavigationController: UINavigationController
{
    var popHandler: (() -> Bool)?

    override func popViewController(animated: Bool) -> UIViewController?
    {
        guard self.popHandler?() != false else
        {
            return nil
        }
        self.popHandler = nil
        return super.popViewController(animated: animated)
    }
}

以及来自跟踪未保存工作的推送控制器的示例使用情况。

let hasUnsavedWork: Bool = // ...
(self.navigationController as! NavigationController).popHandler = hasUnsavedWork ?
    {
        // Prompt saving work here with an alert

        return false // Prevent pop until as user choses to save or discard

    } : nil // No unsaved work, we clear popHandler to let it pop normally

作为一个很好的触摸，这也将被interactivePopGestureRecognizer调用，当用户试图返回使用滑动手势。