ios - UIKeyboard will change frame with interactive keyboard dismiss, not called continuosly -

i trying use uitableview.keyboarddismissmode = uiscrollviewkeyboarddismissmode.interactive, able drag keyboard , down. can't find way track keyboard frame update tableview frame , messaging view. trying replicate standard imessage behaviour. given name, have thought uikeyboardwilchangeframenotification have been perfect tracking keyboard frame changes, notifies when gesture ends , keyboard animates or down.

the best approach interactive dismissal use "uikeyboarddidshownotification" , "uikeyboardwillhidenotification" system notifications. when selector called update table's bottom inset. not constraints. updating inset give beautiful smooth keyboard dismissal experience.