我是这样做的

func showAlert() {
    let alert = UIAlertController(title: "Thanks!", message: "We'll get back to you as soon as posible.", preferredStyle: .alert)

    alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { action in
        self.dismissView()
    }))

    self.present(alert, animated: true)
}

func dismissView() {
    navigationController?.popViewController(animated: true)
    dismiss(animated: true, completion: nil)
}

如果你想关闭前两个视图控制器，只需像这样调用popViewController两次:

self.navigationController?.popViewController(animated: true)
self.navigationController?.popViewController(animated: true)

斯威夫特3

我可能回答得晚了，但对于swift 3，你可以这样做:

override func viewDidLoad() {
    super.viewDidLoad()

    navigationItem.leftBarButtonItem = UIBarButtonItem(title: "< Back", style: .plain, target: self, action: #selector(backAction))

    // Do any additional setup if required.
}

func backAction(){
    //print("Back Button Clicked")
    dismiss(animated: true, completion: nil)
}

试试这个: 对于前面的视图使用这个:

navigationController?.popViewController(animated: true)  

弹出到根目录使用以下代码:

navigationController?.popToRootViewController(animated: true) 

Swift 5及以上

案例1:与导航控制器一起使用

回到之前的视图控制器 self.navigationController ?。会被(动画:真) 回到根视图控制器 self.navigationController ?。popToRootViewController(动画:真)

案例2:使用present视图控制器

self.dismiss(animated: true, completion: nil)

对于swift 3 您只需要编写下面这行代码

_ = navigationController?.popViewController(animated: true)