Ios 处理具有底部约束的键盘

我正在构建一个聊天应用程序，它具有常规的设计和聊天应用程序的用户界面

我有一个工具栏，我的应用程序需要0,0 375x66，我希望它保持在键盘显示时的位置。它有4个约束：顶部：0、前导：0、尾随：0、纵横比：125:22

我有一个UICollectionView 0,66 375x530，当显示键盘时，我想像任何其他聊天应用程序一样滚动它。它有4个约束：从顶部到工具栏：0，前导：0，尾随：0，从底部到newMessageView，我将简要介绍：0

我有一个UIView，里面有一个UIExtField。我们称之为newMessageView 0596 375x71，它有4个约束：底部：0、前导：0、尾随：0、纵横比：375:71

现在，我正在尝试在显示键盘时使用newMessageView应用程序。我正试着这样做：

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y == 0{
            self.newMessageViewBottomConstraint.constant += keyboardSize.height
        }
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y != 0{
            self.newMessageViewBottomConstraint.constant -= keyboardSize.height
        }
    }
}

但它完全不起作用。景色跳跃和隐藏，我真的不明白为什么

我做得对吗？有人能帮我并指导我吗？

你必须使用更新后需要的self.view.layoutifneed

我为你写完整的解决方案

 class ViewController: UIViewController {

        override func viewDidLoad() {
            super.viewDidLoad()

            NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
            NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)

        }

        @objc func keyboardWillShow(notification: Notification) {
            self.keyboardControl(notification, isShowing: true)
        }

        @objc func keyboardWillHide(notification: Notification) {
            self.keyboardControl(notification, isShowing: false)
        }


        private func keyboardControl(_ notification: Notification, isShowing: Bool) {


            /* Handle the Keyboard property of Default*/

            var userInfo = notification.userInfo!
            let keyboardRect = (userInfo[UIKeyboardFrameEndUserInfoKey]! as AnyObject).cgRectValue
            let curve = (userInfo[UIKeyboardAnimationCurveUserInfoKey]! as AnyObject).uint32Value

            let convertedFrame = self.view.convert(keyboardRect!, from: nil)
            let heightOffset = self.view.bounds.size.height - convertedFrame.origin.y
            let options = UIViewAnimationOptions(rawValue: UInt(curve!) << 16 | UIViewAnimationOptions.beginFromCurrentState.rawValue)
            let duration = (userInfo[UIKeyboardAnimationDurationUserInfoKey]! as AnyObject).doubleValue



            var  pureheightOffset : CGFloat = -heightOffset

            if isShowing { /// Wite space of save area in iphonex ios 11
                if #available(iOS 11.0, *) {
                    pureheightOffset = pureheightOffset + view.safeAreaInsets.bottom
                }
            }

            // Here change you Consrant
         //   self.actionBarPaddingBottomConstranit?.update(offset:pureheightOffset)

            UIView.animate(
                withDuration: duration!,
                delay: 0,
                options: options,
                animations: {
                    self.view.layoutIfNeeded()
            },
                completion: { bool in

            })

        }

更新约束后必须使用self.view.layoutifneed

我为你写完整的解决方案

 class ViewController: UIViewController {

        override func viewDidLoad() {
            super.viewDidLoad()

            NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
            NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)

        }

        @objc func keyboardWillShow(notification: Notification) {
            self.keyboardControl(notification, isShowing: true)
        }

        @objc func keyboardWillHide(notification: Notification) {
            self.keyboardControl(notification, isShowing: false)
        }


        private func keyboardControl(_ notification: Notification, isShowing: Bool) {


            /* Handle the Keyboard property of Default*/

            var userInfo = notification.userInfo!
            let keyboardRect = (userInfo[UIKeyboardFrameEndUserInfoKey]! as AnyObject).cgRectValue
            let curve = (userInfo[UIKeyboardAnimationCurveUserInfoKey]! as AnyObject).uint32Value

            let convertedFrame = self.view.convert(keyboardRect!, from: nil)
            let heightOffset = self.view.bounds.size.height - convertedFrame.origin.y
            let options = UIViewAnimationOptions(rawValue: UInt(curve!) << 16 | UIViewAnimationOptions.beginFromCurrentState.rawValue)
            let duration = (userInfo[UIKeyboardAnimationDurationUserInfoKey]! as AnyObject).doubleValue



            var  pureheightOffset : CGFloat = -heightOffset

            if isShowing { /// Wite space of save area in iphonex ios 11
                if #available(iOS 11.0, *) {
                    pureheightOffset = pureheightOffset + view.safeAreaInsets.bottom
                }
            }

            // Here change you Consrant
         //   self.actionBarPaddingBottomConstranit?.update(offset:pureheightOffset)

            UIView.animate(
                withDuration: duration!,
                delay: 0,
                options: options,
                animations: {
                    self.view.layoutIfNeeded()
            },
                completion: { bool in

            })

        }

---

你能分享故事板视图层次结构的屏幕截图吗。我认为你的文本视图隐藏在其他视图后面。你在控制台上看到任何与约束相关的错误吗？@ParthBhuva没有。一切看起来都很好，在xcode中没有errorstry视图调试器在打开键盘后找出你的视图在哪里。你可以共享故事板视图层次结构的屏幕截图吗。我认为您的文本视图隐藏在其他视图后面。您在控制台上看到任何与约束相关的错误吗？@ParthBhuva No。一切看起来都很好，xcode中没有errorstry视图调试器。要在打开键盘后找出您的视图的位置，为了防止悬空的观察者，我建议添加Denit{}视图控制器的例程：NotificationCenter.default.removeObserverself为防止悬空的观察者，建议向视图控制器添加deinit{}例程：NotificationCenter.default.removeObserverself