Question

var longPressTarget: (cell: UICollectionViewCell, indexPath: NSIndexPath)?

func collectionView(collectionView: UICollectionView, didHighlightItemAtIndexPath indexPath: NSIndexPath){
   longPressTarget = (cell: self.collectionView(collectionView, cellForItemAtIndexPath: indexPath), indexPath: indexPath)
}

func longPressHandler(recognizer: UILongPressGestureRecognizer) {
        if recognizer.state == UIGestureRecognizerState.Began {
            if let _longPressTarget = longPressTarget {   
                let entity = coin[_longPressTarget.indexPath.item]
                let contextMenuController = UIAlertController(title: nil, message: nil, preferredStyle: UIAlertControllerStyle.ActionSheet)
                let deleteAction = UIAlertAction(title: entity.pendingDelete ? "Undelete" : "Delete", style: UIAlertActionStyle.Default, handler: togglePendingDelete)
            }
        }
}

错误发生在：let entity = coin[_longPressTarget.indexPath.item]

硬币：

var coin: [Receipts] = [Receipts] ()

在viewDidLoad

之前调用

-coin

收据：核心数据中的实体

我不明白为什么硬币阵列超出范围？

我正在尝试使用长按手势识别器删除UICollectionViewCell核心数据

Answer 1

让我们按部分修复您的代码，首先您不要访问调用方法indexPath的某些cellForItemAtIndexPath:的单元格。您可以像这样使用方法cellForItemAtIndexPath(_:)：

func collectionView(collectionView: UICollectionView, didHighlightItemAtIndexPath indexPath: NSIndexPath) {
     longPressTarget = (cell: self.collectionView?.cellForItemAtIndexPath(indexPath), indexPath: indexPath)
}

然而在你的情况下，我不知道你需要什么细胞但是......

在您的其他方法中，您需要使用indexPath.row而不是indexPath.item，有不同之处。所以你的代码应该是这样的：

func longPressHandler(recognizer: UILongPressGestureRecognizer) {
    if recognizer.state == UIGestureRecognizerState.Began {
        if let _longPressTarget = longPressTarget {
            let indexPath = _longPressTarget.indexPath
            let entity = coin[indexPath.row]
            let contextMenuController = UIAlertController(title: nil, message: nil, preferredStyle: UIAlertControllerStyle.ActionSheet)
            let deleteAction = UIAlertAction(title: entity.pendingDelete ? "Undelete" : "Delete", style: UIAlertActionStyle.Default, handler: togglePendingDelete)
        }
    }
}

我希望这对你有所帮助。

错误：数组索引超出范围Swift

1 个答案: