这并不像我们想象的那么难。只需要为UIButton创建一个背景颜色清晰的框架，为按钮分配动作，并放置在导航栏后退按钮上。最后在使用后取下按钮。

这是Swift 3 用UIImage代替UIButton的示例代码

override func viewDidLoad() {
    super.viewDidLoad()
    let imageView = UIImageView()
    imageView.backgroundColor = UIColor.clear
    imageView.frame = CGRect(x:0,y:0,width:2*(self.navigationController?.navigationBar.bounds.height)!,height:(self.navigationController?.navigationBar.bounds.height)!)
    let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(back(sender:)))
    imageView.isUserInteractionEnabled = true
    imageView.addGestureRecognizer(tapGestureRecognizer)
    imageView.tag = 1
    self.navigationController?.navigationBar.addSubview(imageView)
    }

编写需要执行的代码

func back(sender: UIBarButtonItem) {

    // Perform your custom actions}
    _ = self.navigationController?.popViewController(animated: true)

    }

执行操作后删除子视图

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

    for view in (self.navigationController?.navigationBar.subviews)!{
        if view.tag == 1 {
            view.removeFromSuperview()
        }
    }

斯威夫特3:

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

    if parent == nil{
        print("Back button was clicked")
    }
}

如果你想有后退按钮和后退箭头，你可以使用下面的图片和代码

backArrow.png backArrow@2x.png backArrow@3x.png

override func viewDidLoad() {
    super.viewDidLoad()
    let customBackButton = UIBarButtonItem(image: UIImage(named: "backArrow") , style: .plain, target: self, action: #selector(backAction(sender:)))
    customBackButton.imageInsets = UIEdgeInsets(top: 2, left: -8, bottom: 0, right: 0)
    navigationItem.leftBarButtonItem = customBackButton
}

func backAction(sender: UIBarButtonItem) {
    // custom actions here
    navigationController?.popViewController(animated: true)
}

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 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.")
    }
}

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...
    }
}