Question

iOS 11中引入的新安全区域布局指南非常有效，可防止内容显示在条形下方，但不包括键盘。这意味着当显示键盘时，内容仍然隐藏在其后面，这是我想要解决的问题。

我的方法是基于听取键盘通知，然后通过additionalSafeAreaInsets调整安全区域。

这是我的代码：

override func viewDidLoad() {
    let notificationCenter = NotificationCenter.default
    notificationCenter.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    notificationCenter.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    notificationCenter.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
}

//MARK: - Keyboard
extension MyViewController {
    @objc func keyboardWillShow(notification: NSNotification) {
        let userInfo = notification.userInfo!
        let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height

        additionalSafeAreaInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)
        UIView.animate(withDuration: 0.3) {
            self.view.layoutIfNeeded();
        }
    }

    @objc func keyboardWillHide(notification: NSNotification) {
        additionalSafeAreaInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        UIView.animate(withDuration: 0.3) {
            self.view.layoutIfNeeded();
        }
    }

    @objc func keyboardWillChange(notification: NSNotification) {
        let userInfo = notification.userInfo!
        let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height

        additionalSafeAreaInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)

        UIView.animate(withDuration: 0.3) {
            self.view.layoutIfNeeded();
        }
    }
}

这很有效，因为MyController是UIViewController，UITableView延伸到整个安全区域。现在当键盘出现时，底部被向上推，这样键盘后面就没有单元格了。

问题在于底栏。我底部还有一个工具栏，已经包含在安全区域中。因此，将全键盘高度设置为附加的安全区域插入会将表格视图的底部向上推动过多地与底栏的高度相对应。要使此方法正常运行，我必须将additionalSafeAreaInsets.bottom设置为等于键盘高度减去底栏的高度。

问题1：在底部获得当前安全区间隙的最佳方法是什么？手动获取工具栏框架并使用其高度？或者是否可以直接从安全区域布局指南中获得差距？

问题2：据推测，如果没有键盘改变大小，底栏应该可以改变大小，所以我还应该实现一些方法来监听栏中框架的变化。这最好在viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator)完成吗？还是其他地方？

谢谢

Answer 1

对我来说似乎有用的是计算view.safeAreaLayoutGuide.layoutFrame与键盘框架之间的交点，然后将其高度设置为additionalSafeAreaInsets.bottom，而不是整个键盘框架高度。我的视图控制器中没有工具栏，但我确实有一个标签栏，并且它被正确计算。

完整代码：

import UIKit

public extension UIViewController 
{
    func startAvoidingKeyboard() 
    {    
        NotificationCenter.default
            .addObserver(self,
                         selector: #selector(onKeyboardFrameWillChangeNotificationReceived(_:)),
                         name: UIResponder.keyboardWillChangeFrameNotification,
                         object: nil)
    }

    func stopAvoidingKeyboard() 
    {
        NotificationCenter.default
            .removeObserver(self,
                            name: UIResponder.keyboardWillChangeFrameNotification,
                            object: nil)
    }

    @objc
    private func onKeyboardFrameWillChangeNotificationReceived(_ notification: Notification) 
    {
        guard 
            let userInfo = notification.userInfo,
            let keyboardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue 
        else {
            return
        }

        let keyboardFrameInView = view.convert(keyboardFrame, from: nil)
        let safeAreaFrame = view.safeAreaLayoutGuide.layoutFrame.insetBy(dx: 0, dy: -additionalSafeAreaInsets.bottom)
        let intersection = safeAreaFrame.intersection(keyboardFrameInView)

        let keyboardAnimationDuration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey]
        let animationDuration: TimeInterval = (keyboardAnimationDuration as? NSNumber)?.doubleValue ?? 0
        let animationCurveRawNSN = notification.userInfo?[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
        let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions.curveEaseInOut.rawValue
        let animationCurve = UIView.AnimationOptions(rawValue: animationCurveRaw)

        UIView.animate(withDuration: animationDuration,
                       delay: 0,
                       options: animationCurve,
                       animations: {
            self.additionalSafeAreaInsets.bottom = intersection.height
            self.view.layoutIfNeeded()
        }, completion: nil)
    }
}

Answer 2

如果您需要支持IOS11之前的版本，您可以使用Fabio中的函数并添加：

if #available(iOS 11.0, *) { }

最终解决方案：

extension UIViewController {

    func startAvoidingKeyboard() {
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(_onKeyboardFrameWillChangeNotificationReceived(_:)),
                                               name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                               object: nil)
    }

    func stopAvoidingKeyboard() {
        NotificationCenter.default.removeObserver(self,
                                                  name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                                  object: nil)
    }

    @objc private func _onKeyboardFrameWillChangeNotificationReceived(_ notification: Notification) {
        if #available(iOS 11.0, *) {

            guard let userInfo = notification.userInfo,
                let keyboardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue else {
                    return
            }

            let keyboardFrameInView = view.convert(keyboardFrame, from: nil)
            let safeAreaFrame = view.safeAreaLayoutGuide.layoutFrame.insetBy(dx: 0, dy: -additionalSafeAreaInsets.bottom)
            let intersection = safeAreaFrame.intersection(keyboardFrameInView)

            let animationDuration: TimeInterval = (notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
            let animationCurveRawNSN = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
            let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIViewAnimationOptions.curveEaseInOut.rawValue
            let animationCurve = UIViewAnimationOptions(rawValue: animationCurveRaw)

            UIView.animate(withDuration: animationDuration, delay: 0, options: animationCurve, animations: {
                self.additionalSafeAreaInsets.bottom = intersection.height
                self.view.layoutIfNeeded()
            }, completion: nil)
        }
    }
}

Answer 3

不包括底部安全区域对我有用：

 NSValue keyboardBounds = (NSValue)notification.UserInfo.ObjectForKey(UIKeyboard.FrameEndUserInfoKey);

_bottomViewBottomConstraint.Constant = keyboardBounds.RectangleFValue.Height - UIApplication.SharedApplication.KeyWindow.SafeAreaInsets.Bottom;
                        View.LayoutIfNeeded();

Answer 4

我使用不同的方法。我有一个添加到视图层次结构的视图（KeyboardProxyView）。我将此固定在主视图的底部，然后使用键盘调整其高度。这意味着我们可以像对待键盘视图一样对待keyboardProxy-除了它是普通视图之外，因此您可以对其使用约束。

这使我可以手动限制相对于keyboardProxy的其他视图。

例如-我的工具栏完全没有限制，但是我可能有inputField.bottom> = keyboardProxy.top

下面的代码（注意-我将HSObserver和PureLayout用于通知和自动布局-但如果您希望避免使用它们，则可以轻松地重写该代码）

import Foundation
import UIKit
import PureLayout
import HSObserver

/// Keyboard Proxy view will mimic the height of the keyboard
/// You can then constrain other views to move up when the KeyboardProxy expands using AutoLayout
class KeyboardProxyView: UIView, HSHasObservers {
    weak var keyboardProxyHeight: NSLayoutConstraint!

    override func didMoveToSuperview() {
        keyboardProxyHeight = self.autoSetDimension(.height, toSize: 0)

        let names = [UIResponder.keyboardWillShowNotification,UIResponder.keyboardWillHideNotification]
        HSObserver.init(forNames: names) { [weak self](notif) in
            self?.updateKeyboardProxy(notification: notif)
        }.add(to: self)

        activateObservers()
    }

    var parentViewController: UIViewController? {
        var parentResponder: UIResponder? = self
        while parentResponder != nil {
            parentResponder = parentResponder!.next
            if let viewController = parentResponder as? UIViewController {
                return viewController
            }
        }
        return nil
    }

    func updateKeyboardProxy(notification:Notification){
        let userInfo = notification.userInfo!

        let animationDuration = (userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! NSNumber).doubleValue
        let keyboardEndFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        let convertedKeyboardEndFrame = self.superview!.convert(keyboardEndFrame, from: self.window)
        let rawAnimationCurve = (notification.userInfo![UIResponder.keyboardAnimationCurveUserInfoKey] as! NSNumber).uint32Value << 16
        let animationCurve = UIView.AnimationOptions(rawValue:UInt(rawAnimationCurve))

        keyboardProxyHeight.constant = self.superview!.bounds.maxY - convertedKeyboardEndFrame.minY
        //keyboardProxyHeight.constant = keyboardEndFrame.height

        UIView.animate(withDuration: animationDuration, delay: 0.0, options: [.beginFromCurrentState, animationCurve], animations: {
            self.parentViewController?.view.layoutIfNeeded()
        }, completion: nil)
    }
}

Answer 5

底部插图：

    var safeAreaBottomInset: CGFloat = 0
    if #available(iOS 11.0, *) {
        safeAreaBottomInset = UIApplication.shared.keyWindow?.safeAreaInsets.bottom ?? 0
    }

整个键盘功能：

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    NotificationCenter.default.addObserver(self, selector: #selector(self.onKeyboardWillChangeFrame), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
}

@objc private func onKeyboardWillChangeFrame(_ notification: NSNotification) {
        guard let window = self.view.window,
            let info = notification.userInfo,
            let keyboardFrame = info[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect,
            let duration = info[UIResponder.keyboardAnimationDurationUserInfoKey] as? TimeInterval,
            let animationCurve = info[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
        else {
            return
        }

        var safeAreaInset: CGFloat = 0
        if #available(iOS 11.0, *) {
            safeAreaInset = UIApplication.shared.keyWindow?.safeAreaInsets.bottom ?? 0
        }
        self.keyboardConstraint.constant = max(0, self.view.frame.height - window.convert(keyboardFrame, to: self.view).minY - safeAreaInset)

        UIView.animate(
            withDuration: duration,
            delay: 0,
            options: [UIView.AnimationOptions(rawValue: animationCurve.uintValue), .beginFromCurrentState],
            animations: { self.view.layoutIfNeeded() },
            completion: nil
        )
    }

扩展iOS 11安全区域以包括键盘

5 个答案: