Container View Wont Raise - ios

Question

I have some code that is supposed to raise a container view when the keyboard comes in to enter some text. I feel like I have definitely
implemented this right but the text view is not raising.
var bottomConstraint: NSLayoutConstraint?
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.title = "Comments"
collectionView?.backgroundColor = UIColor.white
self.navigationItem.hidesBackButton = true
let backButton = UIBarButtonItem(image: UIImage(named: "icons8-Back-64"), style: .plain, target: self, action: #selector(GoBack))
self.navigationItem.leftBarButtonItem = backButton
self.collectionView?.register(CommentCell.self, forCellWithReuseIdentifier: cellID)
collectionView?.scrollIndicatorInsets = UIEdgeInsets(top: 0, left: 0, bottom:-50, right: 0)
collectionView?.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: -50, right: 0)
collectionView?.alwaysBounceVertical = true
collectionView?.keyboardDismissMode = .interactive
setupKeyboardObserver()
view.addSubview(containerView)
view.addConstraintsWithFormat("H:|[v0]|", views: containerView)
view.addConstraintsWithFormat("V:[v0(48)]", views: containerView)
Here im setting the constant to 0
let bottomConstraint = NSLayoutConstraint(item: containerView, attribute: .bottom, relatedBy: .equal, toItem: view, attribute: .bottom, multiplier: 1, constant: 0)
view.addConstraint(bottomConstraint)
NotificationCenter.default.addObserver(self, selector: #selector(handleKeyboardNotification), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(handleKeyboardNotification), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
// Register cell classes
// self.collectionView!.register(UICollectionViewCell.self, forCellWithReuseIdentifier: cellID)
fetchComments()
}
Here im taking control of constant and making it react to the keyboard height
func handleKeyboardNotification(notification: NSNotification){
if let userinfo = notification.userInfo{
let keyboardFrame = (userinfo[UIKeyboardFrameEndUserInfoKey] as AnyObject).cgRectValue
bottomConstraint?.constant = -(keyboardFrame?.height)!
let isKeyboardShowing = notification.name == NSNotification.Name.UIKeyboardWillShow
bottomConstraint?.constant = isKeyboardShowing ? CGFloat(-(keyboardFrame?.height)!) : CGFloat(0)
}
}
Despite all this, the keyboard still covers the container view. WHen I change the constant manually it moves but these functions seem to have no effect at dynamically moving the view. I'm confused and any help will be rewarded with a shot at the WWE championship belt. No but seriously I would appreciate the help

Answer 1

What I am able to observe from your code is you are managing the scroll top to down and vice versa with single method you just need to do that with individual method one is while keyboard is appear and another one is while the keyboard is dismiss
Here is the sample snippet which may help you
add the different selector for each notification
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
Handle the keyboard appear and disappear event with following method
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0{
UIView.animate(withDuration: 0.1, animations: { () -> Void in
self.view.frame.origin.y -= keyboardSize.height
})
}
}
}
func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0{
UIView.animate(withDuration: 0.1, animations: { () -> Void in
self.view.frame.origin.y += keyboardSize.height
})
}
}
}
Note:
Do not forgot to remove Observer while your view is going to disappear like
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)

Answer 2

Your handleKeyboardNotification function is setting the constant back to 0 in the last line of the function.
Also, your constant shouldn't be negative keyboard value, it should be the height of the keyboard plus a margin if you need it.

Answer 3

Fixed it by changing bottomConstraint from let to var. Forgot let makes it immutable. Haha guess I'm the WWE champion