Swift 确定集合视图单元格的大小

我正在尝试调整集合视图中特定单元格的大小。好的，我正试着做一个这样的布局

黑色的图像应该是一个图像。所以它应该是一个大图像，然后是两个小图像。好吧，假设我有30张图片。现在我想要0,4,6,10,12,16,18,22,24,28,30的单元格。。。这些是我想要有一个大的形象，但有麻烦的细胞。你可以看到它上升4，然后上升2，依此类推。非常感谢您的帮助

我使用UICollectionViewLayout获得了该设计。我已经用基本逻辑让perRowHeight:CGFloat=190更改了每个单元格的CGRect。在perRowHeight中，我添加了三个单元格。那就是，一个大细胞和两个小细胞

在您的设计中，有六种不同的类型。所以我将indexath.item除以6

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故事板

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水平滚动还是垂直滚动？已启用分页功能？@McDonal_11垂直，在ur屏幕截图中未启用分页功能，6个单元格可见。第0个单元格更大。其余的都较小。@McDonal_11是的，但黑匣子里的应该是一个大图像。如果你有准确的屏幕截图，那么索引为4U的单元格是哪个？你能邮寄吗？

class ImageDesignLayout: UICollectionViewLayout {

    var CellWidth : CGFloat?
var CellHeight : CGFloat?
var cellAttrsDictionary = Dictionary<IndexPath, UICollectionViewLayoutAttributes>()
var contentSize = CGSize.zero

let perRowHeight : CGFloat = 190
var rowCountValue : Int = 0




override var collectionViewContentSize : CGSize {
    return self.contentSize
}

override func prepare() {

    var portrait_Ypos : Double = 0.0
    var xPos : Double = 0.0
    var CELL_WIDTH : Double = 0.0
    var CELL_HEIGHT : Double = 0.0
    rowCountValue = 0

    if let sectionCount = collectionView?.numberOfSections, sectionCount > 0
    {
        for section in 0...sectionCount-1
        {
            if let rowCount = collectionView?.numberOfItems(inSection: section), rowCount > 0
            {
                for item in 0...rowCount-1
                {

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

                    let itemFactor = item % 6

                    print("itemFactoritemFactor   ", itemFactor)

                    switch itemFactor
                    {
                    case 0: // BIG ITEM - LEFT

                        xPos = 0
                        portrait_Ypos = Double(perRowHeight * CGFloat(rowCountValue))
                        CELL_WIDTH = Double(Int((collectionView?.frame.size.width)! * (3/4)))


                        CELL_HEIGHT = Double(perRowHeight)
                        rowCountValue = rowCountValue + 1

                        break
                    case 1:

                        xPos = Double(Int((collectionView?.frame.size.width)! * (3/4)))
                        portrait_Ypos = portrait_Ypos + 0
                        CELL_WIDTH = Double((collectionView?.frame.size.width)!) - xPos
                        CELL_HEIGHT = Double(perRowHeight / 2)


                        break
                    case 2:
                        xPos = Double(Int((collectionView?.frame.size.width)! * (3/4)))
                        portrait_Ypos = portrait_Ypos + Double(perRowHeight / 2)
                        CELL_WIDTH = Double((collectionView?.frame.size.width)!) - xPos
                        CELL_HEIGHT = Double(perRowHeight / 2)

                        break
                    case 3:

                        xPos = 0
                        portrait_Ypos = Double(perRowHeight * CGFloat(rowCountValue))
                        CELL_WIDTH = Double(Int((collectionView?.frame.size.width)! * (1/4)))
                        CELL_HEIGHT = Double(perRowHeight / 2)

                        break
                    case 4:

                        xPos = 0
                        portrait_Ypos = portrait_Ypos + Double(perRowHeight / 2)
                        CELL_WIDTH = Double(Int((collectionView?.frame.size.width)! * (1/4)))
                        CELL_HEIGHT = Double(perRowHeight / 2)

                        break
                    case 5: // BIG ITEM - Right

                        xPos = Double(Int((collectionView?.frame.size.width)! * (1/4)))
                        portrait_Ypos = Double(perRowHeight * CGFloat(rowCountValue))
                        CELL_WIDTH = Double((collectionView?.frame.size.width)!) - xPos
                        CELL_HEIGHT = Double(perRowHeight)

                        rowCountValue = rowCountValue + 1

                        break
                    default:
                        break
                    }

                    let cellAttributes = UICollectionViewLayoutAttributes(forCellWith: cellIndex)
                    cellAttributes.frame = CGRect(x: xPos, y: portrait_Ypos, width: CELL_WIDTH, height: CELL_HEIGHT)

                    cellAttrsDictionary[cellIndex] = cellAttributes
                }
            }
        }
    }

    let contentWidth = UIScreen.main.bounds.width
    let contentHeight = CGFloat(portrait_Ypos) + CGFloat(perRowHeight)
    self.contentSize = CGSize(width: contentWidth, height: contentHeight)

    print("sPort.contentSize     ", self.contentSize)
}

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

    var attributesInRect = [UICollectionViewLayoutAttributes]()

    for cellAttributes in cellAttrsDictionary.values {
        if rect.intersects(cellAttributes.frame) {

            attributesInRect.append(cellAttributes)

        }
    }

    return attributesInRect
}

override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {

    return cellAttrsDictionary[indexPath]!

}



override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
    return true
}

}