Swift

• RAC 监听

func wb_keyboardNotification() {
        NotificationCenter.default.rac_addObserver(forName: UIResponder.keyboardDidShowNotification.rawValue, object: nil).deliverOnMainThread().subscribeNext { [weak self] (notification: NSNotification?) in
            self?.keyboardWillShow(notification: notification!)
        }
        
        NotificationCenter.default.rac_addObserver(forName: UIResponder.keyboardWillChangeFrameNotification.rawValue, object: nil).deliverOnMainThread().subscribeNext { [weak self] (notification: NSNotification?) in
            self?.keyboardWillShow(notification: notification!)
        }
        
        NotificationCenter.default.rac_addObserver(forName: UIResponder.keyboardWillHideNotification.rawValue, object: nil).deliverOnMainThread().subscribeNext { [weak self] (notification: NSNotification?) in
            self?.keyboardWillHide(notification: notification!)
        }
    }

• 系统方法监听

func wb_keyboardNotification() {
        
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object:nil)
        
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object:nil)
    }

• 响应方法

@objc func keyboardWillShow(notification: NSNotification) {
        UIView.animate(withDuration: wb_duration, animations: {
            let keyboardHeight = (notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height
            print(keyboardHeight)
        }, completion: { (finished: Bool) in
            
        })
    }
    
    @objc func keyboardWillHide(notification: NSNotification) {
        UIView.animate(withDuration: wb_duration, animations: {
            let keyboardHeight = (notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height
            print(keyboardHeight)
        }, completion: { (finished: Bool) in
            
        })
    }

• remove observer

deinit {
        NotificationCenter.default.removeObserver(self)
    }

Objective-C

• RAC 监听

- (void)wb_keyboardNotification {
    [[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIKeyboardDidShowNotification object:nil]
      deliverOn:[RACScheduler mainThreadScheduler]]
     subscribeNext:^(NSNotification *value) {
         [UIView animateWithDuration:wb_duration animations:^{
             CGFloat height = [value.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;
             NSLog(@"----------:%f", height);
         } completion:^(BOOL finished) {
             
         }];
     }];
    
    RACSignal *signal = [RACSignal merge:@[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIKeyboardWillChangeFrameNotification object:nil],
                                           [[NSNotificationCenter defaultCenter] rac_addObserverForName:UIKeyboardWillHideNotification object:nil],
                                           ]];
    [[[signal
       takeUntil:[self rac_signalForSelector:@selector(viewWillDisappear:)]]
      deliverOn:[RACScheduler mainThreadScheduler]]
     subscribeNext:^(NSNotification *value) {
         [UIView animateWithDuration:wb_duration animations:^{
             CGFloat height = [value.name isEqualToString:UIKeyboardWillHideNotification] ? 0 : [value.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;
             NSLog(@"----------:%f", height);
         }];
     }];
}