How to dismiss ViewController in Swift?

问题

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?

回答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)

回答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)

回答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")
  }    
}

回答4:

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)
   

回答5:

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)

回答6:

Use:

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

instead of:

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

回答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.

回答8:

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)
   }
   ...
}

回答9:

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)

回答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)
}

回答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..

回答12:

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.

回答13:

If you are presenting a ViewController modally, and want to go back to the root ViewController, take care to dismiss this modally presented ViewController before you go back to the root ViewController otherwise this ViewController will not be removed from Memory and cause Memory leaks.

回答14:

In Swift 3.0

If you want to dismiss a presented view controller

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

回答15:

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)

回答16:

This code written in button action to dismiss

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

回答17:

Try this:

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

回答18:

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

来源：https://stackoverflow.com/questions/24668818/how-to-dismiss-viewcontroller-in-swift