Unwind segue doesn't work SWIFT

Question

I have a navigation controller, with a table view. When I press a cell, the detail view controller opens.

In my root view controller I have :

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

    if segue.identifier == "detailview" {    
        var destination:DetailViewController = segue.destinationViewController as DetailViewController
        destination.delegate=self   
    }
}

In my detail view controller I have a back button :

@IBAction func back() {        
    self.navigationController?.popViewControllerAnimated(true)    
}

The issue is, after 2 go to and return, my app crashes when I go back on the root view controller pressing back button. The console doesn't give me errors. It just crashes.

I think I have forgotten to unwind the segue. So in my detail view controller I added :

@IBAction func unwindToViewController(segue: UIStoryboardSegue) {
    println("unwind function")
}

I connect this function to my back button with "exit" in my storyboard.

When I run my app, If I press on the back button, the console doesn't display my print "unwind function", so unwindToViewController isn't called. Why ?

And my app still crashes...

zisoft zisoft · Accepted Answer · 2015-01-03T11:45:25

Your unwindToViewController method should be placed in your root viewController, then ctrl-drag from the button in the detailViewController to the Exit icon in InterfaceBuilder. Choose that method in the popup menu.

Another approach would be to declare a protocol with a function in the rootViewController that is called from the detailViewController. You already set the rootViewController as the delegate of the detailViewController. Within that function you call dismissViewController.

Unwind segue doesn't work SWIFT

2 Answers