Question

我有一个parent容器UIView，它有三个子视图：1个UITextView和2个按钮（按钮位于UITextView的顶部，但包含为容器UIView的子视图）。当我在屏幕上正常显示父UIView时，只需在UIViewController内部，按钮就能完美地触发相关的动作方法并正常运行。但是，当我在一个成为弹出窗口的视图控制器中呈现UIView时，视图层次结构会正确显示，但按钮不会触发其关联的操作方法，也不会发生任何事情。是否有关于我不理解的UIPopoverPresentationController和按钮的内容？

将按钮添加到父UIView

func layoutButtons(in parent: UIView) {
    let speechButton = UIButton(type: .custom)
    speechButton.frame = CGRect(x: parent.frame.width - 35, y: parent.frame.height - 35, width: 30, height: 30)
    speechButton.setImage(UIImage(named: "sound_icon"), for: .normal)
    speechButton.addTarget(self, action: #selector(Textual.textToSpeech), for: UIControlEvents.touchUpInside)
    parent.addSubview(speechButton)

    let fontSizeButton = UIButton(type: .custom)
    fontSizeButton.frame = CGRect(x: textView.frame.width - 75, y: textView.frame.height - 35, width: 30, height: 30)
    fontSizeButton.setImage(UIImage(named: "font_size_icon"), for: .normal)
    fontSizeButton.addTarget(self, action: #selector(Textual.toggleFontSize), for: UIControlEvents.touchUpInside)
    parent.addSubview(fontSizeButton)

    // wrap text around the bottom buttons
    let excludeSpeechButton = UIBezierPath(rect: speechButton.frame)
    let excludeFontSizeButton = UIBezierPath(rect: fontSizeButton.frame)
    self.textView.textContainer.exclusionPaths = [excludeSpeechButton, excludeFontSizeButton]
}

@objc func textToSpeech() {
    if synth.isPaused {
        synth.continueSpeaking()
    } else if synth.isSpeaking {
        synth.pauseSpeaking(at: .immediate)
    } else {
        let speechUtterance = AVSpeechUtterance(string: attributedText.string)
        speechUtterance.rate = 0.5
        synth.speak(speechUtterance)
    }
}

@objc func toggleFontSize() {

    if self.smallFontSizeMode == true {
        self.smallFontSizeMode = false
    } else {
        self.smallFontSizeMode = true
    }

    // for each character, multiply the current font size by fontSizeModifier
    // http://stackoverflow.com/questions/19386849/looping-through-nsattributedstring-attributes-to-increase-font-size

    self.attributedText.beginEditing()

    self.attributedText.enumerateAttribute(NSFontAttributeName, in: NSMakeRange(0, self.attributedText.length), options: NSAttributedString.EnumerationOptions.reverse, using: { (value, range, stop) in
        if let oldFont = value as? UIFont {
            var newFont: UIFont?
            if self.smallFontSizeMode == true { // was big and now toggling to small
                newFont = oldFont.withSize(oldFont.pointSize / 2)
            } else { // was small and now toggling to big
                newFont = oldFont.withSize(oldFont.pointSize * 2)
            }
            attributedText.removeAttribute(NSFontAttributeName, range: range)
            attributedText.addAttribute(NSFontAttributeName, value: newFont!, range: range)
        }
    })

    self.attributedText.endEditing()

    self.textView.attributedText = self.attributedText

}

呈现UIViewController

func present(viewController: UIViewController, at location: CGRect) {

    viewController.modalPresentationStyle = .popover
    parentViewController.present(viewController, animated: true, completion: nil)

    let popController = viewController.popoverPresentationController
    popController?.permittedArrowDirections = .any
    popController?.sourceView = parentView
    popController?.sourceRect = location

}

更新 - 我已将popController?.delegate = viewController添加为func present(viewController:at:)的最后一行，而我已添加extension UIViewController: UIPopoverPresentationControllerDelegate { }

Answer 1

要回答您的问题，您需要告诉您的呈现视图控制器谁委派，所以请在下面添加以下内容并让我知道它是否有效：

popController?.delegate = viewController

UIButton正常工作，但不能在popoverPresentationController

1 个答案: