iOS键盘通知使用

Swift 5

今天用change notification的时候，出现键盘始终不收起的bug，最后还是采用了 Show, Hide的方式， 特此记录一下

func registeNotifications() {
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(keyboardWillShow(_:)),
                                               name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(keyboardWillHide(_:)),
                                               name: UIResponder.keyboardWillHideNotification, object: nil)
        // change 关闭键盘，发现iOS 14.7上不收起键盘，原因未知
//        NotificationCenter.default.addObserver(self, selector: #selector(keyboardFrameChanged(_:)), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    }

 @objc func keyboardWillShow(_ noti: Notification) {
        guard let _ = noti.userInfo else {
            return
        }
        
        let duration = noti.keyboardAnimationDuration()
        
        let cureAnimation = noti.keyboardAnimationCurve()
        
        let keyboardHeight = noti.keyboardHeight()
        
        inputBar.snp.updateConstraints { make in
            make.bottom.equalTo(self.view.snp.bottom).offset(-keyboardHeight)
        }
        
        UIView.animate(withDuration: duration, delay: 0.0, options: cureAnimation) {
            self.view.layoutIfNeeded()
        } completion: { _ in
            
        }
    }
    
    @objc func keyboardWillHide(_ noti: Notification) {
        guard let _ = noti.userInfo else {
            return
        }
        let duration = noti.keyboardAnimationDuration()
        
        let cureAnimation = noti.keyboardAnimationCurve()
        
        inputBar.snp.updateConstraints { make in
            make.bottom.equalTo(self.view.snp.bottom).offset(0)
        }
        
        UIView.animate(withDuration: duration, delay: 0.0, options: cureAnimation) {
            self.view.layoutIfNeeded()
        } completion: { _ in
            
        }
    }

Notification extension

extension Notification {
    func keyboardHeight() -> CGFloat {
        if let userInfo = self.userInfo, let value = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
            let size = value.cgRectValue.size
            return size.height
        }
        return 0
    }
    
    func keyboardAnimationCurve() -> UIView.AnimationOptions {
        if let userInfo = self.userInfo {
            if let curveValue = (userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber)?.uintValue {
                return UIView.AnimationOptions(rawValue: curveValue << 16)
            }
        }
        return UIView.AnimationOptions.curveEaseInOut
    }
    
    func keyboardAnimationDuration() -> Double {
        if let userInfo = self.userInfo {
            if let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double {
                return duration
            }
        }
        return 0.25
    }
}