在我的例子中，viewWillDisappear效果最好。但在某些情况下，必须修改之前的视图控制器。所以这是我的解决方案访问之前的视图控制器，它在Swift 4中工作:

override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        if isMovingFromParentViewController {
            if let viewControllers = self.navigationController?.viewControllers {
                if (viewControllers.count >= 1) {
                    let previousViewController = viewControllers[viewControllers.count-1] as! NameOfDestinationViewController
                    // whatever you want to do
                    previousViewController.callOrModifySomething()
                }
            }
        }
    }

NO

override func willMove(父控件:UIViewController?) {}

即使你在segue到覆盖这个方法的视图控制器，这个也会被调用。其中，检查parent是否为nil或not不是确保移动回正确的UIViewController的精确方法。为了准确地确定UINavigationController是否正确地导航回呈现当前的UIViewController，你将需要遵守UINavigationControllerDelegate协议。

YES

注意:MyViewController只是你想要检测返回的UIViewController的名称。

1)在你的文件顶部添加UINavigationControllerDelegate。

class MyViewController: UIViewController, UINavigationControllerDelegate {

2)添加一个属性到你的类，它将跟踪你正在segue的UIViewController。

class MyViewController: UIViewController, UINavigationControllerDelegate {

var previousViewController:UIViewController

3)在MyViewController的viewDidLoad方法中为你的UINavigationController分配self作为委托。

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController?.delegate = self
}

3)在你segue之前，将之前的UIViewController分配为这个属性。

// In previous UIViewController
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "YourSegueID" {
        if let nextViewController = segue.destination as? MyViewController {
            nextViewController.previousViewController = self
        }
    }
}

4)并遵循UINavigationControllerDelegate的MyViewController中的一个方法

func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
    if viewController == self.previousViewController {
        // You are going back
    }
}

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
    })

一种选择是实现您自己的自定义后退按钮。你需要添加以下代码到你的viewDidLoad方法:

    - (void) viewDidLoad {
        [super viewDidLoad];
        self.navigationItem.hidesBackButton = YES;
        UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStyleBordered target:self action:@selector(back:)];
        self.navigationItem.leftBarButtonItem = newBackButton;
    }

    - (void) back:(UIBarButtonItem *)sender {
        // Perform your custom actions
        // ...
        // Go back to the previous ViewController
        [self.navigationController popViewControllerAnimated:YES];
    }

更新:

以下是Swift的版本:

        override func viewDidLoad {
            super.viewDidLoad()
            self.navigationItem.hidesBackButton = true
            let newBackButton = UIBarButtonItem(title: "Back", style: UIBarButtonItemStyle.Bordered, target: self, action: "back:")
            self.navigationItem.leftBarButtonItem = newBackButton
        }

       @objc func back(sender: UIBarButtonItem) {
            // Perform your custom actions
            // ...
            // Go back to the previous ViewController
            self.navigationController?.popViewControllerAnimated(true)
        }

更新2:

以下是Swift 3的版本:

        override func viewDidLoad {
            super.viewDidLoad()
            self.navigationItem.hidesBackButton = true
            let newBackButton = UIBarButtonItem(title: "Back", style: UIBarButtonItemStyle.plain, target: self, action: #selector(YourViewController.back(sender:)))
            self.navigationItem.leftBarButtonItem = newBackButton
        }

       @objc func back(sender: UIBarButtonItem) {
            // Perform your custom actions
            // ...
            // Go back to the previous ViewController
            _ = navigationController?.popViewController(animated: true)
        }

斯威夫特4.2:

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

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

    }
}

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...
    }
}