如何显示 UICollectionViewCell 的 MenuController？

Question

我如何重现 iPhone 上消息的复制粘贴功能，如果您长按一条消息，消息单元格会变成灰色，并且会出现一个带有“复制”的小弹出窗口。如何在我的 UICollectionViewCells 上显示相同的菜单？

Answer 1

事实证明，他的功能已经内置并且就像实现三个collectionView: 委托方法一样简单。我创建了一个协议CopyableCell，其属性名为copyableProperty，这是一个单元格要复制到剪贴板的字符串，我可以复制的单元格必须遵循该字符串。从那时起就很简单了：

  func collectionView(collectionView: UICollectionView, shouldShowMenuForItemAtIndexPath indexPath: NSIndexPath) -> Bool {
    if let _ = collectionView.cellForItemAtIndexPath(indexPath) as? CopyableCell {
      return true
    }
    return false
  }
  func collectionView(collectionView: UICollectionView, canPerformAction action: Selector, forItemAtIndexPath indexPath: NSIndexPath, withSender sender: AnyObject?) -> Bool {
    if action.description == "copy:" {
      return true
    }

    return false
  }

  func collectionView(collectionView: UICollectionView, performAction action: Selector, forItemAtIndexPath indexPath: NSIndexPath, withSender sender: AnyObject?) {
    //No more checking is needed here since we only allow for copying
    if let cell = collectionView.cellForItemAtIndexPath(indexPath) as? CopyableCell {
      UIPasteboard.generalPasteboard().string = cell.copyableProperty
    }
  }