无法在 CollectionViewCell 的按钮中添加带有参数的目标 (Swift 4) [英] Cannot add target with parameters in CollectionViewCell's button (Swift 4)

问题描述

我的 CollectionViewCell 中有一个按钮，我想在点击按钮时触发 UIActivityViewController(通过 URL).

There is a button in my CollectionViewCell, I would like to trigger the UIActivityViewController (with an URL passing) when the button tapped.

我正在尝试向 CollectionViewCell 中的按钮添加目标(带参数)，但似乎不起作用，这是我的代码:

I'm trying to add a target (with parameter) to the button which is in CollectionViewCell, but it seems it doesn't work, here are my codes:

  override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: verticalCellId, for: indexPath) as! VerticalCellId

    if let articleURL = self.card?[indexPath.item]._uRLAddress {

    cell.shareButton.addTarget(self, action: #selector(shareButtonPressed(sharedURL: articleURL)), for: .touchUpInside)

   }

}


  @objc func shareButtonPressed(sharedURL: String) {

    let shareText = sharedURL
    let activityViewController : UIActivityViewController = UIActivityViewController(activityItems: [shareText], applicationActivities: nil)
    activityViewController.popoverPresentationController?.sourceView = self.view
    self.present(activityViewController, animated: true, completion: nil)
}

错误是:'#selector' 的参数不引用'@objc' 方法、属性或初始化程序

它在没有参数传递时效果很好，就像这样:

It just works well when no parameters passing, like this:

 override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: verticalCellId, for: indexPath) as! VerticalCellId

    if let articleURL = self.card?[indexPath.item]._uRLAddress {

    cell.shareButton.addTarget(self, action: #selector(shareButtonPressed), for: .touchUpInside)

   }

}

@objc func shareButtonPressed() {

    let shareText = NSLocalizedString("Share our app with friends.", comment: "share")
    let activityViewController : UIActivityViewController = UIActivityViewController(activityItems: [shareText], applicationActivities: nil)
    activityViewController.popoverPresentationController?.sourceView = self.view
    self.present(activityViewController, animated: true, completion: nil)
}

任何建议将不胜感激.

推荐答案

您不能在目标/动作选择器中传递任意参数.

You cannot pass an arbitrary parameter in a target/action selector.

支持的形式是

• 无参数
• 一个必须是动作发送者的参数 (shareButtonPressed(_ sender: UIButton))
• 一些 UIControl 项目还允许额外的 UIControlEvents 参数.

• No parameter
• One parameter which must be the sender of the action (shareButtonPressed(_ sender: UIButton))
• Some UIControl items allow also an additional UIControlEvents parameter.

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