How to write Keyboard notifications in Swift 3

Question

I\'m trying to update this code to swift 3:

NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector(\"keyboardWillShow:\"), name: UIKeyboar         


        

Answer 1

Swift 5.1 + Combine + SwiftUI

@State var keyboardHeight: CGFloat = 0 // or @Published if one is in ViewModel: ObservableObject

private var cancellableSet: Set = []
    
init() {
            
   let notificationCenter = NotificationCenter.default
        
   notificationCenter.publisher(for: UIWindow.keyboardWillShowNotification)
       .map {
             guard
                 let info = $0.userInfo,
                 let keyboardFrame = info[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect
                 else { return 0 }

             return keyboardFrame.height
         }
         .assign(to: \.keyboardHeight, on: self)
         .store(in: &cancellableSet)
        
     notificationCenter.publisher(for: UIWindow.keyboardDidHideNotification)
         .map { _ in 0 }
         .assign(to: \.keyboardHeight, on: self)
         .store(in: &cancellableSet)
    }