ios - UIKeyboardWillHideNotification 动画延迟

Question

我已经注册了两个 UIKeyboardNotifications(keyboardWillShow 和 keyboardWillHide)并且都被触发了。当文本字段移回原始位置的动画仅在键盘消失后才被触发时，问题就出现了。有没有办法减少获取通知和动画文本字段之间的延迟？

func keyboardWillShow(notification: NSNotification) {
    let info = notification.userInfo!
    let keyboardFrame : CGRect = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()
    duration = (info[UIKeyboardAnimationDurationUserInfoKey]?.doubleValue)
    let rawAnimationCurve = (notification.userInfo![UIKeyboardAnimationCurveUserInfoKey] as! NSNumber).unsignedIntValue << 16
    animationCurve = UIViewAnimationOptions(rawValue: UInt(rawAnimationCurve))
    let moveAmount = keyboardFrame.height
    UIView.animateWithDuration(duration!, delay:0, options: animationCurve, animations: {
        self.txtfield.transform = CGAffineTransformMakeTranslation(0.0, -self.moveAmount)
        }, completion:nil)
}

func keyboardWillHide(notification: NSNotification) {
        UIView.animateWithDuration(duration, delay:0, options:animationCurve, animations: {
            self. txtfield.transform = CGAffineTransformMakeTranslation(0.0, 0.0)
            }, completion:nil)
}

GIF image here

Answer 1

意识到一个问题，是我粗心的错误。

添加:

NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(viewController.keyboardDidHide), name: UIKeyboardWillHideNotification, object: nil)

代替:

NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(viewController.keyboardWillHide), name: UIKeyboardWillHideNotification, object: nil)