iOS 11 - Keyboard Height is returning 0 in keyboard notification

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

Use this:

CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;

For Swift, you can use:

let keyboardSize = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.size

Replace UIKeyboardFrameBeginUserInfoKey

with

UIKeyboardFrameEndUserInfoKey

The below is from Apple Docs.

UIKeyboardFrameBeginUserInfoKey- The key for an NSValue object containing a CGRect that identifies the start frame of the keyboard in screen coordinates.

UIKeyboardFrameEndUserInfoKey - The key for an NSValue object containing a CGRect that identifies the end frame of the keyboard in screen coordinates.

SolinLiu

Try this:

Replace UIKeyboardFrameBeginUserInfoKey with UIKeyboardFrameEndUserInfoKey

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.

Sujay U N

This issue is happening on iOS 11.

Replace

"UIKeyboardFrameBeginUserInfoKey" with "UIKeyboardFrameEndUserInfoKey"

as shown below would fix the issue

Objective-C Code :

CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;

Swift 2.3 :

let keyboardSize = (NfnPsgVar.userInfo![UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue().size

Swift 3 :

let keyboardSize = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.size

Calculate keyboard height using below code. It is working for both devices with the safe area and non-safe area devices.

@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
    }
}

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.

来源：https://stackoverflow.com/questions/45689664/ios-11-keyboard-height-is-returning-0-in-keyboard-notification

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ios

objective-c

nsnotificationcenter