如何在 Swift 中关闭 ViewController？

Question

I am trying to dismiss a ViewController in swift by calling dismissViewController in an IBAction

  @IBAction func cancel(sender: AnyObject) {
    self.dismissViewControllerAnimated(false, completion: nil)
    println("cancel")
}

@IBAction func done(sender: AnyObject) {
    self.dismissViewControllerAnimated(false, completion: nil)
    println("done")
}

I could see the println message in console output but ViewController never gets dismissed. What could be the problem?

Answer 1

From you image it seems like you presented the ViewController using push

The dismissViewControllerAnimated is used to close ViewControllers that presented using modal

Swift 2

navigationController.popViewControllerAnimated(true)

Swift 4

navigationController?.popViewController(animated: true)

dismiss(animated: true, completion: nil)

Answer 2

I have a solution for your problem. Please try this code to dismiss the view controller if you present the view using modal:

Swift 3:

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

OR

If you present the view using "push" segue

self.navigationController?.popViewController(animated: true)

Answer 3

if you do this i guess you might not get println message in console,

@IBAction func cancel(sender: AnyObject) {
  if(self.presentingViewController){
    self.dismissViewControllerAnimated(false, completion: nil)
    println("cancel")
   }
}

@IBAction func done(sender: AnyObject) {
  if(self.presentingViewController){
    self.dismissViewControllerAnimated(false, completion: nil)
    println("done")
  }    
}

Answer 4

In Swift 3.0 to 4.0 it's as easy as typing this into your function:

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

Or if you're in a navigation controller you can "pop" it:

self.navigationController?.popViewController(animated: true)

Answer 5

1. embed the View you want to dismiss in a NavigationController
2. add a BarButton with "Done" as Identifier
3. invoke the Assistant Editor with the Done button selected
4. create an IBAction for this button

5. add this line into the brackets:

    self.dismissViewControllerAnimated(true, completion: nil)

Answer 6

Use:

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

instead of:

self.navigationController.dismissViewControllerAnimated(true, completion: nil)

Answer 7

If you presenting a controller without a Navigation Controller, you can call the following code from a method of the presented controller.

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

If your ViewController is presented modally, optional presentingViewController will be not nil and the code will be executed.

Answer 8

From Apple documentations :

The presenting view controller is responsible for dismissing the view controller it presented

Thus, it is a bad practise to just invoke the dismiss method from it self.

What you should do if you're presenting it modal is:

presentingViewController?.dismiss(animated: true, completion: nil)

Answer 9

Based on my experience, I add a method to dismiss me as extension to UIViewController:

extension UIViewController {
    func dismissMe(animated: Bool, completion: (()->())?) {
        var count = 0
        if let c = self.navigationController?.viewControllers.count {
            count = c
        }
        if count > 1 {
            self.navigationController?.popViewController(animated: animated)
            if let handler = completion {
                handler()
            }
        } else {
            dismiss(animated: animated, completion: completion)
        }
    }
}

Then I call this method to dismiss view controller in any UIViewController subclass. For example, in cancel action:

class MyViewController: UIViewController {
   ...
   @IBAction func cancel(sender: AnyObject) {
     dismissMe(animated: true, completion: nil)
   }
   ...
}

Answer 10

Don't create any segue from Cancel or Done to other VC and only write this code your buttons @IBAction

@IBAction func cancel(sender: AnyObject) {
    dismiss(animated: false, completion: nil)
}

Answer 11

Here is the one way to dismiss present view controller and move back to previous view controller. You can do this through Storyboard only.

1. Open Storyboard
2. Right click on Cancel button and drag it to previous view controller, where you want to move back to previous controller
3. Now release the right click and you can see some actions which performs on cancel button
4. Now choose "popover present" option from list
5. Now you can dismiss your current view by click on cancel button

Please try this, It's working with me.

Second Way - Use - navigationController.popViewControllerAnimated(true)

Best luck..

Answer 12

由于您使用了推送呈现的视图控制器，因此，您可以使用

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

Answer 13

For reference, be aware that you might be dismissing the wrong view controller. For example, if you have an alert box or modal showing on top of another modal. (You could have a Twitter post alert showing on top of your current modal alert, for example). In this case, you need to call dismiss twice, or use an unwind segue.

Answer 14

So if you wanna dismiss your Viewcontroller use this. This code is written in button action to dismiss VC

  @IBAction func cancel(sender: AnyObject) {
   dismiss(animated: true, completion: nil)
  }

Answer 15

Try this:

@IBAction func close() {
  dismiss(animated: true, completion: nil)
}

Answer 16

If you using the present method in the parent VC then you should call this function, to dismiss the child VC use this

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

if you calling child VC by using push method, to dismiss the child VC use this

self.navigationController?.popViewController(animated: true)

Answer 17

如果您以模态方式呈现一个 ViewController，并且想返回到根 ViewController，请在返回根 ViewController 之前注意关闭这个以模态方式呈现的 ViewController，否则该 ViewController 将不会从内存中删除并导致内存泄漏。

Answer 18

In Swift 3.0

If you want to dismiss a presented view controller

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

Answer 19

In Swift 4.1 and Xcode 9.4.1

If you use pushViewController to present new view controller, use this

self.navigationController?.popViewController(animated: false)

Answer 20

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