swift 3.0

Question

我有一个UIScrollView和一个UITextView，就像在任何消息/聊天应用中一样，当UIScrollView向下滚动时，键盘也会被交互式拖动。

我需要在滚动UIScrollView时检测键盘高度，我尝试了UIKeyboardWillChangeFrame观察者，但是在释放滚动点按后会调用此事件。

在不知道键盘高度的情况下，我无法更新UITextView底部约束，并且我在键盘和底部视图之间得到了一个间隙@screenshot。

同时附加来自Viber的屏幕截图，当从滚动条拖动键盘时对齐底部栏也可以在WhatsApp中看到。

Answer 1

从iOS 10开始，当NSNotification ，UIScrollView以交互方式拖动键盘时，Apple不提供UIKeyboardWillChangeFrame观察员来检测帧更改只有一次释放水龙头才会发现UIKeyboardDidChangeFrame。

无论如何，在查看DAKeyboardControl库后，我有意在UIScrollView.UIPanGestureRecognizer附加UIViewController，因此生成的所有手势事件都将在UIViewController中处理同样。拧了好几个小时后，我开始工作，这里是所有必需的代码：

class ViewController: UIViewController, UIGestureRecognizerDelegate { fileprivate let collectionView = UICollectionView(frame: .zero) private let bottomView = UIView() fileprivate var bottomInset: NSLayoutConstraint! // This holds height of keypad private var maxKeypadHeight: CGFloat = 0 { didSet { self.updateCollectionViewInsets(maxKeypadHeight + self.bottomView.frame.height) self.bottomInset.constant = -maxKeypadHeight } } private var isListeningKeypadChange = false override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) NotificationCenter.default.addObserver(self, selector: #selector(keypadWillChange(_:)), name: .UIKeyboardWillChangeFrame, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(keypadWillShow(_:)), name: .UIKeyboardWillShow, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(keypadWillHide(_:)), name: .UIKeyboardWillHide, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(keypadDidHide), name: .UIKeyboardDidHide, object: nil) } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) NotificationCenter.default.removeObserver(self) } func keypadWillShow(_ notification: Notification) { guard !self.isListeningKeypadChange, let userInfo = notification.userInfo as? [String : Any], let animationDuration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval, let animationCurve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt, let value = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return } self.maxKeypadHeight = value.cgRectValue.height let options = UIViewAnimationOptions.beginFromCurrentState.union(UIViewAnimationOptions(rawValue: animationCurve)) UIView.animate(withDuration: animationDuration, delay: 0, options: options, animations: { [weak self] in self?.view.layoutIfNeeded() }, completion: { finished in guard finished else { return } // Some delay of about 500MS, before ready to listen other keypad events DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { [weak self] in self?.beginListeningKeypadChange() } }) } func handlePanGestureRecognizer(_ pan: UIPanGestureRecognizer) { guard self.isListeningKeypadChange, let windowHeight = self.view.window?.frame.height else { return } let barHeight = self.bottomView.frame.height let keypadHeight = abs(self.bottomInset.constant) let usedHeight = keypadHeight + barHeight let dragY = windowHeight - pan.location(in: self.view.window).y let newValue = min(dragY < usedHeight ? max(dragY, 0) : dragY, self.maxKeypadHeight) print("Old: \(keypadHeight) New: \(newValue) Drag: \(dragY) Used: \(usedHeight)") guard keypadHeight != newValue else { return } self.updateCollectionViewInsets(newValue + barHeight) self.bottomInset.constant = -newValue } func keypadWillChange(_ notification: Notification) { if self.isListeningKeypadChange, let value = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue { self.maxKeypadHeight = value.cgRectValue.height } } func keypadWillHide(_ notification: Notification) { guard let userInfo = notification.userInfo as? [String : Any] else { return } self.maxKeypadHeight = 0 var options = UIViewAnimationOptions.beginFromCurrentState if let animationCurve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt { options = options.union(UIViewAnimationOptions(rawValue: animationCurve)) } let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval UIView.animate(withDuration: duration ?? 0, delay: 0, options: options, animations: { self.view.layoutIfNeeded() }, completion: nil) } func keypadDidHide() { self.collectionView.panGestureRecognizer.removeTarget(self, action: nil) self.isListeningKeypadChange = false if (self.maxKeypadHeight != 0 || self.bottomInset.constant != 0) { self.maxKeypadHeight = 0 } } private func beginListeningKeypadChange() { self.isListeningKeypadChange = true self.collectionView.panGestureRecognizer.addTarget(self, action: #selector(self.handlePanGestureRecognizer(_:))) } fileprivate func updateCollectionViewInsets(_ value: CGFloat) { let insets = UIEdgeInsets(top: 0, left: 0, bottom: value + 8, right: 0) self.collectionView.contentInset = insets self.collectionView.scrollIndicatorInsets = insets } }

Answer 2

swift 3.0

您可以尝试这种方式，我已在我的项目中实施。希望它会对你有所帮助。

@IBOutlet weak var constant_ViewBottom: NSLayoutConstraint! // 0

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

   override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }

func keyboardWillShow(_ notification: NSNotification){
        if let keyboardRectValue = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size {
            let keyboardHeight = keyboardRectValue.height
            print("keyboardHeight:=\(keyboardHeight)")
            constant_ViewBottom.constant = keyboardHeight
            self.view.layoutIfNeeded()
        }
    }
 func keyboardWillHide(_ notification: NSNotification){
        constant_ViewBottom.constant = 0.0
        self.view.layoutIfNeeded()
    }

Answer 3

看起来你有一个底部约束的错误常数。尝试每次重置底部约束并设置新的高度值

    func keyboardDidChangeFrame(notification: Notification) {
        if let userInfo = notification.userInfo {
            if let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
                let duration: TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
                let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
                let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIViewAnimationOptions().rawValue
                let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)
                if endFrame.origin.y >= UIScreen.main.bounds.size.height {
                    self.inputBarBottomSpacing.constant = 0
                } else {
                   //the most important logic branch, reset current bottom constant constraint value
                    if self.inputBarBottomSpacing.constant != 0 {
                        self.inputBarBottomSpacing.constant = 0
                    }
                    self.inputBarBottomSpacing.constant = -endFrame.size.height
                }
                UIView.animate(withDuration: duration, delay: TimeInterval(0), options: animationCurve, animations: {
                    self.view.layoutIfNeeded()
                }, completion: nil)
            }
        }
    }

Answer 4

您只需添加此广告连结：

   IOTEvent.State    .attrs.EventTime DataEvent.Model DataEvent.DataType DataEvent.DataValue
1:        PowerOn 2017-02-27T18:33:58              NA                 NA                  NA
2:             NA 2017-02-28T08:59:03               1                  1                0301
3:             NA 2017-02-28T08:59:13               1                  1                0401

然后在 AppDelegate.swift 中添加：

pod 'IQKeyboardManagerSwift'

import IQKeyboardManagerSwift函数中的a

didFinishLaunchingWithOptions

这很简单。

向下滚动UIScrollView并以交互方式拖动键盘时检测键盘高度

4 个答案:

swift 3.0