How to use Objective C selectors as arguments when subscribing to NSNotifications?

Question

I have the following subscription in swift. I need to know when the keyboard will show to move the view up. It compiles and works as expected but I don't know how to get rid of this warning. "No method declared with Objective-C selector'keyboardWillShow'"

// Subscribing class to recieve the notification
func subscribeToKeyboardNotifications() {
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow", name: UIKeyboardWillShowNotification, object: nil)
}
// Shifting view's frame up
func keyboardWillShow(notification: NSNotification) {
    view.frame.origin.y -= getKeyboardHeight(notification)
}
// Getting keyboard height
func getKeyboardHeight(notification: NSNotification) -> CGFloat {
    let userInfo = notification.userInfo
    let keyboardSize = userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue // of CGRect
    return keyboardSize.CGRectValue().height
}

Thanks in advance for any suggestions!

Please, check this answer, http://stackoverflow.com/questions/36366116/no-method-declared-with-objective-c-selector-for-notification-uikeyboardwillshow — Sanoj Kashyap, Aug 31 '16 at 18:46

score 1 · Accepted Answer · answered Aug 31 '16 at 18:41

1

Use #selector:

NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)

answered Aug 31 '16 at 18:41

JAL

40,662
22
162
292

Thanks for your answer and pointing up that this question was already answered :) I didn't find it on google or as a duplicate while making the question. – Mateo Villagomez Aug 31 '16 at 19:10

How to use Objective C selectors as arguments when subscribing to NSNotifications?

1 Answers1