iPhone X 键盘显示额外 space

Question

我创建了一个聊天 UI，其中我在屏幕底部为 tableView 添加了一个 constraint。我正在通过添加键盘高度来更改约束值，这在除 iPhone X.

以外的所有设备中都可以正常工作

UI 当键盘不可见时：

很好。

问题是当键盘显示为空白时 space 在 textView 和键盘之间可见：

我是否必须为此尝试不同的方法，或者可以使用约束来解决？

Answer 1

发泄你对 ViewController 的约束。我现在将其称为 yourConstraint。然后添加代码以发现何时显示键盘以及何时关闭键盘。您可以在那里相应地更改约束的 constant 。这允许您继续使用约束。

在viewWillAppear中：

NotificationCenter.default.addObserver(self, selector: #selector(YourViewController.keyboardWillShow), name:        NSNotification.Name.UIKeyboardWillShow, object: nil) // <=== Replace YourViewController with name of your view controller
NotificationCenter.default.addObserver(self, selector: #selector(YourViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil) // <=== Replace YourViewController with name of your view controller

在viewWillDisappear中：

NotificationCenter.default.removeObserver(self)

在你的UIViewController

@objc private func keyboardWillShow(notification: Notification) {
    guard let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue else {
        yourConstraint.isActive = false // <=== 
        view.layoutIfNeeded()
        return
    }
    let duration: TimeInterval = ((notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue) ?? 0.4
    yourConstraint.constant = newValue // <===
    UIView.animate(withDuration: duration) {
        self.view.layoutIfNeeded()
    }
}

@objc private func keyboardWillHide(notification: Notification) {
    let duration: TimeInterval = ((notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue) ?? 0.4
    yourConstraint.constant = oldValue
    UIView.animate(withDuration: duration) {
        self.view.layoutIfNeeded()
    }
}

UIView.animate 不是必需的（块内部是必需的），但它使过渡看起来不错。

Answer 2

在计算约束值时尝试减去安全区域底部插图的高度。

这是一个处理 UIKeyboardWillChangeFrame 通知的示例实现。

@objc private func keyboardWillChange(_ notification: Notification) {
    guard let userInfo = (notification as Notification).userInfo, let value = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
    let newHeight: CGFloat
    if #available(iOS 11.0, *) {
        newHeight = value.cgRectValue.height - view.safeAreaInsets.bottom
    } else {
        newHeight = value.cgRectValue.height
    }
    myConstraint.value = newHeight
}

Answer 3

UIKeyboardFrameBeginUserInfoKey报告的键盘值在iPhone X:

这两种情况下是不同的

键盘不可见，文本字段成为第一响应者
键盘已经可见，不同的文本字段成为第一响应者。

要获得键盘的最终高度（包括安全区域插入）使用 UIKeyboardFrameEndUserInfoKey.

在iOS11（特别是iPhoneX）中，可以考虑减去安全区底部的insets

    NSValue *keyboardEndFrameValue = notification.userInfo[UIKeyboardFrameEndUserInfoKey];
    if (keyboardEndFrameValue != nil) {
        CGRect keyboardSize = [keyboardEndFrameValue CGRectValue];
        _keyboardHeight = keyboardSize.size.height;
        if (@available(iOS 11.0, *)) {
            CGFloat bottomSafeAreaInset = self.view.safeAreaInsets.bottom;
            _keyboardHeight -= bottomSafeAreaInset;
        } else {
            // Fallback on earlier versions
        }
    }

Answer 4

Swift 4/5 iPhone X 我不得不稍微调整内森的回答才能让它发挥作用。这个是 100%。

注意：确保您已将控制权从故事板的 textView/view 的底部约束拖动到 ViewController 中安全区域的底部，并且您还控制了拖动和创建目标视图控制器的项目导航器中的出口。我在示例中将其命名为 bottomConstraint。我的文本输入字段包含在一个视图 (MessageInputContainerView) 中，以允许额外的发送按钮对齐等。

代码如下：

@objc private func keyboardWillChange(_ notification: Notification) {
    guard let userInfo = (notification as Notification).userInfo, let value = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue else {
        return
    }
    
    if ((userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue) != nil {
        let isKeyboardShowing = notification.name == NSNotification.Name.UIKeyboardWillShow
        var newHeight: CGFloat
        if isKeyboardShowing {
            if #available(iOS 11.0, *) {
                newHeight = value.cgRectValue.height - view.safeAreaInsets.bottom
                bottomConstraint.constant = newHeight
                
            }
        }
        else {
            newHeight = value.cgRectValue.height
            bottomConstraint?.constant = view.safeAreaInsets.bottom + messageInputContainerView.bounds.height

        }
    }
}

Answer 5

我的问题是我的视图位于子视图控制器中。转换 CGRect 就成功了。

@objc private func keyboardWillChangeFrame(notification: NSNotification) {
    guard let userInfo = notification.userInfo, let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue, let duration: TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue else {
        return
    }

    let convertedFrame = view.convert(endFrame, from: nil)
    let endFrameY = endFrame.origin.y

    let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
    let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIViewAnimationOptions.curveEaseInOut.rawValue
    let animationCurve: UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)

    if endFrameY >= UIScreen.main.bounds.size.height {
        inputContainerViewBottomLayoutConstraint.constant = 0.0
    }  else {
        var newHeight = view.bounds.size.height - convertedFrame.origin.y
        if #available(iOS 11.0, *) {
            newHeight = newHeight - view.safeAreaInsets.bottom
        }
        inputContainerViewBottomLayoutConstraint.constant = newHeight
    }

    UIView.animate(withDuration: duration, delay: TimeInterval(0), options: animationCurve, animations: {
        self.view.layoutIfNeeded()
    },completion: { _ in
        self.scrollView.scrollToBottom()
    })
}

Answer 6

这对我有用

TL;DR：self.view.safeAreaInsets.bottom 返回 0。关键是使用 UIApplication.shared.keyWindow.safeAreaInsets.bottom 而不是。

让 replyField 成为感兴趣的 UITextField。

1) 在viewDidLoad()中添加观察者。

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)

2) 设置class内的全局变量作为约束

var textFieldBottomConstraintKeyboardActive : NSLayoutConstraint?
var textFieldBottomConstraintKeyboardInactive : NSLayoutConstraint?

3) 在 viewDidLoad 调用的函数中设置约束。

let replyFieldKeyboardActiveConstraint = self.replyField.bottomAnchor.constraint(
    equalTo: self.view.safeAreaLayoutGuide.bottomAnchor,
    constant: -1 * Constants.DEFAULT_KEYBOARD_HEIGHT /* whatever you want, we will change with actual height later */ + UITabBar.appearance().frame.size.height
)

let replyFieldKeyboardInactiveConstraint = self.replyField.bottomAnchor.constraint(
    equalTo: self.view.safeAreaLayoutGuide.bottomAnchor
)

self.textFieldBottomConstraintKeyboardActive = replyFieldKeyboardActiveConstraint
self.textFieldBottomConstraintKeyboardInactive = replyFieldKeyboardInactiveConstraint

self.textFieldBottomConstraintKeyboardActive?.isActive = false
self.textFieldBottomConstraintKeyboardInactive?.isActive = true

4) 定义keyboardWillShow 和keyboardWillHide 方法。这里的关键是我们如何在 keyboardWillShow 方法中定义 heightOffset。

@objc func keyboardWillShow(notification: NSNotification) {
    guard let userinfo = notification.userInfo else {
        return
    }
    guard let keyboardSize = userinfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {
        return
    }
    let keyboardFrame = keyboardSize.cgRectValue

    self.view.layoutIfNeeded()

    let heightOffset = keyboardFrame.height - UITabBar.appearance().frame.height - (UIApplication.shared.keyWindow?.safeAreaInsets.bottom ?? 0)

    self.textFieldBottomConstraintKeyboardActive?.constant = -1 * heightOffset

    self.textFieldBottomConstraintKeyboardActive?.isActive = true
    self.textFieldBottomConstraintKeyboardInactive?.isActive = false

    self.view.setNeedsLayout()
}


@objc func keyboardWillHide(notification: NSNotification) {
    self.textFieldBottomConstraintKeyboardActive?.isActive = false
    self.textFieldBottomConstraintKeyboardInactive?.isActive = true
}

iPhone X 键盘显示额外 space

iPhone X keyboard appear showing extra space

ios

swift

iphone-x