How to Get Height of Keyboard

How to get height of Keyboard?

Swift

You can get the keyboard height by subscribing to the UIKeyboardWillShowNotification notification. (Assuming you want to know what the height will be before it's shown).

Swift 4

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: UIResponder.keyboardWillShowNotification,
    object: nil
)

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}

Swift 3

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: NSNotification.Name.UIKeyboardWillShow,
    object: nil
)

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}

Swift 2

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

func keyboardWillShow(notification: NSNotification) {
        let userInfo: NSDictionary = notification.userInfo!
        let keyboardFrame: NSValue = userInfo.valueForKey(UIKeyboardFrameEndUserInfoKey) as! NSValue
        let keyboardRectangle = keyboardFrame.CGRectValue()
        let keyboardHeight = keyboardRectangle.height
    }

Is there any way in Android to get the height of virtual keyboard of device

Yes you can, with the help of Viewtree Observer and global layout listener, just try below mentioned steps

Get the root view of your layout
get the Viewtree observer for this root, and add a global layout listener on top of this.

now whenever soft keyboard is displayed android will re-size your screen and you will receive call on your listener. That's it only thing you now need to do is calculate difference between height which your root view has after re-size and original size. If difference is more then 150 consider this as a keyboard has been inflated.

Below is a sample code

root.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener(){
     public void onGlobalLayout(){
           int heightDiff = root.getRootView().getHeight()- root.getHeight();
           // IF height diff is more then 150, consider keyboard as visible.  
        }
  });

Regards,
Techfist

How to get a height of a Keyboard in React-Native?

This is what I did:

If the app has "Authorization / Log-in / Sign-up screen" then:

In componentWillMount add KeyboardListeners as explained here:

this.keyboardDidShowListener = Keyboard.addListener('keyboardDidShow', this._keyboardDidShow);
this.keyboardDidHideListener = Keyboard.addListener('keyboardDidHide', this._keyboardDidHide);

Add autoFocus to e-mail / phone number / any other "first" TextInput on the page, so that when the screen loads, the Keyboard pops-up.

In _keyboardDidShow function, that is used as a KeyboardListener, do the follows:

_keyboardDidShow(e) {
    this.props.navigation.setParams({
        keyboardHeight: e.endCoordinates.height,
        normalHeight: Dimensions.get('window').height, 
        shortHeight: Dimensions.get('window').height - e.endCoordinates.height, 
    }); 
}

Dimensions is an API of React-Native, do not forget to import it just like you import any React-Native component.

After that, while redirecting to the next page, pass these params and do not forget to keep on passing them to other screens in order not to lose this data:
```
this.props.navigation.navigate('pageName', { params: this.props.navigation.state.params });
```