解决方法
添加两个观察者
NSNotificationCenter.defaultCenter().addObserver(self,selector: "keyboardVisible:",name: UIKeyboardDidShowNotification,object: nil)
NSNotificationCenter.defaultCenter().addObserver(self,selector: "keyboardHidden:",name: UIKeyboardDidHideNotification,object: nil)
func keyboardVisible(notif: NSNotification) {
print("keyboardVisible")
}
func keyboardHidden(notif: NSNotification) {
print("keyboardHidden")
}
