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iOS

Posted by Steven Rayzman
Steven Rayzman
2,423 Points

How to prepare for back button segue?

I am using a UINavigation controller, and when I press on the back button item, I need to execute a particular piece of code (To make the array empty again). How would I accomplish this using swift. Stone Preston

1 Answer

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

see this stack overflow post

you should implement didMoveToParentViewCOntroller:

- (void)didMoveToParentViewController:(UIViewController *)parent
{
    if (![parent isEqual:self.parentViewController]) {
         NSLog(@"Back pressed");
    }
}

in swift that would probably look something like:

override func didMoveToParentViewController(parent: UIViewController) {

  if !parent.isEqual(self.parentVIewController) {

        println("Back button pressed")

  }

}

you may have to play around with that a bit.

Steven Rayzman
Steven Rayzman
2,423 Points

How would the code look, using swift? Thanks again

Stone Preston
Stone Preston
42,016 Points

see my answer above. you are probably going to have to tweak that a bit.

Steven Rayzman
Steven Rayzman
2,423 Points

How could I make it so that when the back button of the UINavigation Controller is pressed, than the unwind segue is executed. Stone Preston

Stone Preston
Stone Preston
42,016 Points

im not sure thats possible without creating your own UIBarButtonItem that acts as the back button. see this stack overflow post on how to create unwind segues. its very detailed with lots of screenshots.

Steven Rayzman
Steven Rayzman
2,423 Points

Thanks for the stack overflow post. Another way would be to just set the array to be empty once the back button is pressed. How could I do that? Stone Preston