Swift - 使用 UIKeyboardWillChangeFrame 时关闭键盘并调用 TouchUpInside 按钮同时不起作用

Question

我正在使用 swift，并且 TouchUpInside 出现问题:如果我使用 UIKeyboardWillChangeFrame 或 UIKeyboardWillShow/UIKeyboardWillHide，并且键盘正在显示，并且当键盘最初显示时，我尝试按下的按钮位于键盘后面。 (如果我向下滚动到按钮直到可见并按下，则不会调用 touchUpInside)。

无论键盘是否显示，TouchDown 似乎都能一致工作，但 TouchUpInside 不会被调用。如果键盘最初显示时按钮位于键盘顶部上方，则 TouchUpInside 可以工作。我使用 KeyboardNotification 设置 ScrollView 下方 View 的高度，以便在键盘显示时升起 ScrollView 。据我所知，通常只有当按钮是 ScrollView 中的最后一个元素时才会出现这种情况(因此当显示键盘时可能位于键盘后面)。

@IBOutlet var keyboardHeightLayoutConstraint: NSLayoutConstraint?
@IBOutlet weak var textField: UITextField!
@IBOutlet weak var saveButton: UIButton!
@IBAction func saveTouchUpInside(_ sender: UIButton) {
   print("touchupinside = does not work")
}
@objc func saveTouchDown(notification:NSNotification){
   print("touchdown = works")
}

View 将出现:

textField.delegate = self

NotificationCenter.default.addObserver(self,selector:#selector(self.keyboardNotification(notification:)),name: 

NSNotification.Name.UIKeyboardWillChangeFrame,object: nil)
self.saveButton.addTarget(self, action:#selector(ViewController.saveTouchDown(notification:)), for: .touchDown)

deinit {
    NotificationCenter.default.removeObserver(self)
}

@objc func keyboardNotification(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
        let endFrameY = endFrame?.origin.y ?? 0
        let duration:TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
        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 {
            self.keyboardHeightLayoutConstraint?.constant = 0.0
        } else {
            self.keyboardHeightLayoutConstraint?.constant = endFrame?.size.height ?? 0.0
        }
            UIView.animate(withDuration: duration, delay: TimeInterval(0),options: animationCurve, animations: { self.view.layoutIfNeeded() }, completion: nil)
        }
    }

我想关闭键盘并同时调用 saveTouchUpInside，而不使用 TouchDown。

Answer 1

我将键盘交互抽象为一个单独的类，这样我的 Controller 就不会变得臃肿(也遵循关注点分离)。这是我使用的键盘管理器类。

import UIKit


/**
*  To adjust the scroll view associated with the displayed view to accommodate
*  the display of keyboard so that the view gets adjusted accordingly without getting hidden
*/
class KeyboardManager {

    private var scrollView: UIScrollView

    /**
    *  -parameter scrollView: ScrollView that need to be adjusted so that it does not get clipped by the presence of the keyboard
    */
    init(scrollView: UIScrollView) {

        self.scrollView = scrollView

        let notificationCenter = NotificationCenter.default
        notificationCenter.addObserver(self,
                                                                     selector: #selector(adjustForKeyboard),
                                                                     name: UIResponder.keyboardWillHideNotification, object: nil)
        notificationCenter.addObserver(self,
                                                                     selector: #selector(adjustForKeyboard),
                                                                     name: UIResponder.keyboardDidChangeFrameNotification, object: nil)
    }

    /**
    * Indicates that the on-screen keyboard is about to be presented.
    *  -parameter notification: Contains animation and frame details on the keyboard
    *
    */
    @objc func adjustForKeyboard(notification: Notification) {

        guard let containedView = scrollView.superview else { return }

        let userInfo = notification.userInfo!
        let keyboardScreenEndFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        let keyboardViewEndFrame = containedView.convert(keyboardScreenEndFrame, to: containedView.window)

        let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! NSNumber
        let rawAnimationCurveValue = (userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as! NSNumber).uintValue

        UIView.animate(withDuration: TimeInterval(truncating: duration),
                                     delay: 0,
                                     options: [UIView.AnimationOptions(rawValue: rawAnimationCurveValue)],
                                     animations: {

                                        if notification.name == UIResponder.keyboardWillHideNotification {
                                            self.scrollView.contentInset = UIEdgeInsets.zero
                                        } else {
                                            self.scrollView.contentInset = UIEdgeInsets(top: 0,
                                                                                                                                    left: 0,
                                                                                                                                    bottom: keyboardViewEndFrame.height,
                                                                                                                                    right: 0)
                                        }

                                        self.scrollView.scrollIndicatorInsets = self.scrollView.contentInset

        },
                                     completion: nil)
    }

    deinit {
        let notificationCenter = NotificationCenter.default
        notificationCenter.removeObserver(self)
    }

}

它的用法是这样的

• 创建对键盘管理器的引用

 private var keyboardManager: KeyboardManager!

• 并在viewDidLoad中分配键盘管理器类，其中self.scrollView是您正在使用的scrollView

 self.keyboardManager = KeyboardManager(scrollView: self.scrollView)

这应该可以解决这个问题。如果这不起作用，示例项目可能有助于深入了解这一点。