iOS 11 - Keyboard Height is returning 0 in keyboard notification

user_970957 0
Viewed 21656

I have been using Keyboard notifications without any problem and getting exact height of Keyboard.

- (void)keyboardDidShow:(NSNotification *) notification{
    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    NSLog(@"%f",keyboardSize.height);}

but with iOS 11 the size of keyboard is 0 when the notification is called.

What is the problem occurring in this scenario? I am using xcode 9 Beta 5

nsnotificationcenter objective-c ios
8 Answers

I had a similar issue using Xcode Version 9.0 (9A235); although I was using Swift. In my keyboardWillShow method I wrote the following:

if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {

    let heightValue = keyboardSize.height    

    ...
}

Strangely, the first time keyboardWillShow was called, heightValue was 216.0, but during subsequent calls it had become 0! Perhaps this is an Xcode bug.

I replaced the UIKeyboardFrameBeginUserInfoKey with a UIKeyboardFrameEndUserInfoKey, and it fixed the issue for me.

user_57622200

Calculate keyboard height using the below code.

It is working for both devices with the safe area and non-safe area devices.

Code:

@objc func keyboardWillShow(notification: Notification) {
    guard let keyboardFrame = notification.userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {
            return
        }    
    let keyboardHeight: CGFloat                    
    if #available(iOS 11.0, *) {
       let window = UIApplication.shared.keyWindow
       let bottomPadding = window?.safeAreaInsets.bottom ?? 0.0
       keyboardHeight = keyboardFrame.cgRectValue.height - bottomPadding
    } else {
       keyboardHeight = keyboardFrame.cgRectValue.height
    }
}
user_50365860

Your approach is trying to get the frame height before it is shown, and that is why it should be 0 which I am not sure why it is not at the first try! Here is an example of how to correctly get the keyboard height in swift 4.2:

func keyboardWillShow(notification: Notification) {

    guard let userInfo = notification.userInfo else { return }

    guard var keyboardFrame: CGRect = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue else { return }

    keyboardFrame = view.convert(keyboardFrame, from: nil)

    let keyboardHeight = keyboardFrame.height
}

This will correctly provide the keyboard frame properties BEFORE keyboard appears.

user_71600850

Eventhough we get accurate keyboard height when we adjust BottomSpace Constraints from SafeArea it makes more empty space. So we have to subtract safeArea margin from keyboard height if we are going to adjust the bottomSpace Constraints.

    @objc func keyBoardWillShow(notification: NSNotification) {
                  
    
                  if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
                      var bottomPadding: CGFloat = 0
                      //IF device is latest including iPhone x, it will have bottom padding as safeArea Insets. So we have to subtract that from REAL Keyboard HEIGHT.
                      if let window = UIApplication.shared.windows.first{
                        bottomPadding = window.safeAreaInsets.bottom
                      }
    
                      let keyboardRectangle = keyboardFrame.cgRectValue
                      let keyboardHeight = keyboardRectangle.height - bottomPadding
                      bottomSpaceConstraint.constant = keyboardHeight
                  }
                  self.view.layoutIfNeeded()
              }
user_50448880
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