ios - 如何从类属性(特别是 UIButton)访问父类实例？

Question

我有一个聊天气泡按钮，它调用一个菜单来将文本或图像复制到粘贴板。当我处理长按和双击时，我可以访问按钮本身，但是我需要能够访问包含在聊天气泡按钮旁边的单元格实例中的消息属性。

我的目标是使用从操作函数传递的 cell.chatBubble 引用来检索对单元格的引用，以便访问 message 数据。

func selfMessageCellForRowAtIndexPath(indexPath: NSIndexPath) -> SelfMessageCell {
    let cell = self.tableView.dequeueReusableCellWithIdentifier(SelfMessageCellIdentifier) as! SelfMessageCell

    let message = self.messages[indexPath.row]

    cell.messageLabel.text = message.messageContents
    let messageWidth = cell.messageLabel.intrinsicContentSize().width
    if messageWidth < (cell.bounds.width * 0.7 - 42) {
        cell.chatWidth = messageWidth + 33
    }

    cell.chatBubble.addGestureRecognizer(UILongPressGestureRecognizer(target: self, action: #selector(handleCopyGesture(_:))))

    cell.chatBubble.addGestureRecognizer(UILongPressGestureRecognizer(target: self, action: #selector(handleCopyGesture(_:))))
    let tap = UITapGestureRecognizer(target: self, action: #selector(handleCopyGesture(_:)))
    tap.numberOfTapsRequired = 2
    cell.chatBubble.addGestureRecognizer(tap)

    cell.transform = self.tableView.transform

    return cell
}


// Extension for chat bubble press handling
extension MessageSuperViewController {
func handleCopyGesture(recognizer: UIGestureRecognizer) {
    if recognizer.state == UIGestureRecognizerState.Began {
        openCopyMenu(recognizer)
    }
    else if !UIMenuController.sharedMenuController().menuVisible{
        openCopyMenu(recognizer)
    }
}

func openCopyMenu(recognizer: UIGestureRecognizer) {
    if let recognizerView = recognizer.view, recognizerSuperView = recognizer.view?.superview {
        let menuController = UIMenuController.sharedMenuController()
        let copyItem = UIMenuItem(title: "Copy", action: #selector(copyMessageContents(_:)))
        let moreItem = UIMenuItem(title: "More..", action: #selector(moreMenuItem(_:)))
        menuController.menuItems = [copyItem,moreItem]
        menuController.setTargetRect(recognizerView.frame, inView: recognizerSuperView)
        menuController.setMenuVisible(true, animated: true)
        recognizerView.becomeFirstResponder()
    }
}

func copyMessageContents(sender: UIMenuItem) {

}

func moreMenuItem(sender: UIMenuItem) {

}

Answer 1

我建议在 SelfMessageCell 中添加 UITapGestureRecognizer，当您触发事件时，您可以使用如下委托(delegate):

SelfMessageCellDidTapDelegate(sender: SelfMessageCell)

并且在您拥有 selfMessageCellForRowAtIndexPath 的此类中，您实现了此委托(delegate)，sender 将包含您想要的数据。

func selfMessageCellForRowAtIndexPath(indexPath: NSIndexPath) -> SelfMessageCell {
    let cell = self.tableView.dequeueReusableCellWithIdentifier(SelfMessageCellIdentifier) as! SelfMessageCell
    cell.delegate = self
    ....
}

SelfMessageCellDidTapDelegate(sender: SelfMessageCell) {
    print(sender)
}