Question

我有一个像Pinterest一样定制的UICollectionView。我将此归档this Ray Wenderlich Tutorial。我在这里完成了一切，它完美无缺。尝试从集合视图中删除单元格时出现问题。我使用此函数进行删除：

extension PintViewController:FavouriteOffersDelegate{

func collectionViewCellDidTapHeart(_ sender: PntCollectionViewCell) {
    guard let indexTapped = collectionView.indexPath(for: sender) else {
        return
    }
    let id:Int = generalsOffersArray[indexTapped.row].id
    print(indexTapped.item)
    generalsOffersArray.remove(at: indexTapped.item)
    collectionView.deleteItems(at: [indexTapped])

    }
}

我理解问题必须在我使用的库中，但我是Swift的新手，并且无法清楚地了解我应该修改或移除的内容以使其工作。当执行此代码时，我得到的错误是控制台：

2017-10-18 17：25：20.637123 + 0200 RemoveItemsPinterest [1017：432532] *断言失败 - [UICollectionViewData validateLayoutInRect：]，/ BuildRoot / Library / Cache / com.apple.xbs / Sources /的UIKit / UIKit的-3694.4.18 / UICollectionViewData.m：435 2017-10-18 17：25：20.638356 + 0200 RemoveItemsPinterest [1017：432532] * 由于未捕获的异常终止应用程序＆＃39; NSInternalInconsistencyException＆＃39;，原因：＆＃39; UICollectionView接收到的布局属性索引路径不存在的单元格：{length = 2，path = 0 - 12}＆＃39; ***第一次抛出调用堆栈：（0x1833bfd38 0x1828d4528 0x1833bfc0c 0x183d4ec24 0x18c82b834 0x18c82ab8c 0x18d2964ac 0x18d2412b8 0x18d241218 0x18d241148 0x18c82a1cc 0x18c7cd000 0x18739d0b4 0x1873a1194 0x18730ff24 0x187336340 0x18ca33744 0x18d112718 0x18d10b574 0x183368358 0x1833682d8 0x183367b60 0x183365738 0x1832862d8 0x185117f84 0x18c833880 0x1000c8ee4 0x182daa56c） libc ++ abi.dylib：以NSException类型的未捕获异常终止

布局对象的代码：

class PinterestLayout: UICollectionViewLayout {
var delegate:PinterestLayoutDelegate!

var numberOfColumns = 2
var cellPadding: CGFloat = 5.0

fileprivate var cache = [PinterestLayoutAttributes]()

fileprivate var contentHeight:CGFloat  = 0.0
fileprivate var contentWidth: CGFloat {
    let insets = collectionView!.contentInset
    return collectionView!.bounds.width - (insets.left + insets.right)
}

override class var layoutAttributesClass : AnyClass {
    return PinterestLayoutAttributes.self
}

override func prepare() {
    if cache.isEmpty {

        let columnWidth = contentWidth / CGFloat(numberOfColumns)
        var xOffset = [CGFloat]()
        for column in 0 ..< numberOfColumns {
            xOffset.append(CGFloat(column) * columnWidth )
        }
        var column = 0
        var yOffset = [CGFloat](repeating: 0, count: numberOfColumns)

        for item in 0 ..< collectionView!.numberOfItems(inSection: 0) {

            let indexPath = IndexPath(item: item, section: 0)

            let width = columnWidth - cellPadding*2
            let photoHeight = delegate.collectionView(collectionView!, heightForPhotoAtIndexPath: indexPath , withWidth:width)
            let annotationHeight = delegate.collectionView(collectionView!, heightForAnnotationAtIndexPath: indexPath, withWidth: width)
            let height = cellPadding +  photoHeight + annotationHeight + cellPadding
            let frame = CGRect(x: xOffset[column], y: yOffset[column], width: columnWidth, height: height)
            let insetFrame = frame.insetBy(dx: cellPadding, dy: cellPadding)

            let attributes = PinterestLayoutAttributes(forCellWith: indexPath)
            attributes.photoHeight = photoHeight
            attributes.frame = insetFrame
            cache.append(attributes)

            contentHeight = max(contentHeight, frame.maxY)
            yOffset[column] = yOffset[column] + height

            column = column >= (numberOfColumns - 1) ? 0 : column + 1
        }
    }
}

override var collectionViewContentSize : CGSize {
    return CGSize(width: contentWidth, height: contentHeight)
}

override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
    var layoutAttributes = [UICollectionViewLayoutAttributes]()

    // Loop through the cache and look for items in the rect
    for attributes  in cache {
        if attributes.frame.intersects(rect ) {
            layoutAttributes.append(attributes)
        }
    }
    return layoutAttributes
}
}

从像Pinterest这样的自定义UICollectionView中删除单元格

0 个答案: