如何通过使用Swift单击完成按钮来关闭以前的和当前的视图控制器

Question

I have three view controllers (VC1, VC2, VC3) . Here, VC1 add button click to present VC2 then VC2 I have another one add button for make a VC3 present. VC3 I have navigation bar cancel and done button. If I click I can able to dismiss and show VC2 but If I click done button I need to show VC1 (Between VC1 and VC3 need to dismiss VC2). How to achieve this?

I am using below code for presenting and dismissing

VC1

@IBAction func presentFirst(_ sender: Any) {
    let firstvc = self.storyboard?.instantiateViewController(withIdentifier: "firstcontroller") as! FirstViewController
    let navigationController = UINavigationController(rootViewController: firstvc)
    self.present(navigationController, animated: true, completion: nil)
}

VC2

 @IBAction func presentSecond(_ sender: Any) {
        let secondtvc = self.storyboard?.instantiateViewController(withIdentifier: "secondcontroller") as! SecondViewController
        let navigationController = UINavigationController(rootViewController: secondtvc)
        self.present(navigationController, animated: true, completion: nil)
    }



     @IBAction func doneAction(_ sender: Any) {
            self.dismiss(animated: true, completion: nil)
        }

        @IBAction func cancelAction(_ sender: Any) {
            self.dismiss(animated: true, completion: nil)
        }

VC3

@IBAction func doneAction(_ sender: Any) {
    // Need to dismiss current and previous VC2 
}

@IBAction func cancelAction(_ sender: Any) {
    self.dismiss(animated: true, completion: nil)
}

Answer 1

A good practice would be to use prepare(for segue: at VC2 in order to send a reference of its self to VC3 so you can dismiss it later.

• So first of all add a reference variable in VC3

   var vc2Ref: VC2! 

• Then in VC2 you can set this variable's value like this

   override func prepare(for segue: UIStoryboardSegue, sender: Any?) { if let vc3 = segue.destination as? VC3 { vc3.vc2Ref = self } } 

• And now you are able to dismiss VC2 and VC3

   @IBAction func doneAction(_ sender: Any) { //dismiss current VC3 self.dismiss(animated: true, completion: nil) //dismiss previous VC2 self.vc2Ref.dismiss(animated: true, completion: nil) } 

Answer 2

About dismiss() method document .

Discussion

If you present several view controllers in succession, thus building a stack of presented view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack. When this happens, only the top-most view is dismissed in an animated fashion; any intermediate view controllers are simply removed from the stack. The top-most view is dismissed using its modal transition style, which may differ from the styles used by other view controllers lower in the stack.

In brief, if a presented stack is as following,

A -> B -> C -> D -> E

// A.present(B), then B.present(C), ... , D.present(E) 
// E is top-most view controller.

If call E.dismiss() , then the stack will be

A -> B -> C -> D

Then, if call C.dismiss() , then stack will be

A -> B

// NOTE:
// Don't call `E.dismiss()`, `D.dismiss()`, `C.dismiss()` in sequence.
// ONLY call `C.dismiss()`. Just as the `Discussion` said.