如何在collectionView自定义布局中的其他补充标题单元格上方添加标题补充单元格

Question

So I have a custom layout collectionView that looks something like this:

I did this with the help of @McDonal_11 with a custom layout [not a flowLayout ] that basically allows my collectionView to display each section with it's items in a separate column.

The thing is that I want to add a supplementary header above all these supplementary headers that is not part of the sections .

something like this:

How should I do so?

Answer 1

Below changes you will get close to that result.

For Portrait, I have Changed xPosition and Cell width for Section 0 and item 0

For Landscape, I have Changed xPosition , yPosition and Cell width for Section 0 and item 0.

I did some logic for Cell should be centre of SuperView .

override func prepare() {

    dataSourceDidUpdate = false

    if UIDevice.current.orientation == .landscapeLeft || UIDevice.current.orientation == .landscapeRight
    {
        if let sectionCount = collectionView?.numberOfSections, sectionCount > 0 {
            for section in 0...sectionCount-1 {

                let maxNum = max(section, sectionCount + 1)
                let minNum = min(section, sectionCount + 1)

                let difference = maxNum - minNum

                var xPos = (Double(UIScreen.main.bounds.width) - (Double(difference) * CELL_WIDTH) - (Double(difference) * horizontalSpacing))

                var yPos : Double = 35.0

                if let rowCount = collectionView?.numberOfItems(inSection: section), rowCount > 0 {

                    for item in 0...rowCount-1 {


                        xPos = (Double(UIScreen.main.bounds.width) - (Double(difference) * CELL_WIDTH) - (Double(difference) * horizontalSpacing))

                        CELL_WIDTH = 100.0

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

                        if item == 0
                        {
                            portrait_Ypos = headerSpacing + 30
                        }
                        else
                        {
                            portrait_Ypos = portrait_Ypos + CELL_HEIGHT + verticalSpaing
                        }
                        yPos = portrait_Ypos

                        if section == 0 && item == 0
                        {
                            xPos = 20
                            yPos = 0.0
                            CELL_WIDTH = (Double(UIScreen.main.bounds.width)) - 40
                        }


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


                        xPos = (Double(UIScreen.main.bounds.width) - (Double(difference) * CELL_WIDTH) - (Double(difference) * horizontalSpacing))

                        CELL_WIDTH = 100.0
                        yPos = 35.0

                        // Determine zIndex based on cell type.
                        if section == 0 && item == 0 {
                            cellAttributes.zIndex = 4
                        } else if section == 0 {
                            cellAttributes.zIndex = 3
                        } else if item == 0 {
                            cellAttributes.zIndex = 2
                        } else {
                            cellAttributes.zIndex = 1
                        }
                        cellAttrsDictionary[cellIndex] = cellAttributes

                    }

                }

            }
        }

        let contentWidth = Double(collectionView!.numberOfSections) * CELL_WIDTH + (Double(collectionView!.numberOfSections - 1) * horizontalSpacing)
        let contentHeight = Double(collectionView!.numberOfSections) * CELL_HEIGHT
        self.contentSize = CGSize(width: contentWidth, height: contentHeight)

        print("self.contentSizeself.contentSize     ", self.contentSize)
    }
    else
    {
        if let sectionCount = collectionView?.numberOfSections, sectionCount > 0 {

            for section in 0...sectionCount-1 {

                var xPos = (Double(UIScreen.main.bounds.width) - CELL_WIDTH) / 2.0

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

                        xPos = (Double(UIScreen.main.bounds.width) - CELL_WIDTH) / 2.0
                        CELL_WIDTH = 100.0

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

                        if section != 0
                        {
                            if item == 0
                            {
                                portrait_Ypos = portrait_Ypos + CELL_HEIGHT + headerSpacing
                            }
                            else
                            {

                                portrait_Ypos = portrait_Ypos + CELL_HEIGHT + verticalSpaing
                            }
                        }
                        else
                        {
                            if item == 0
                            {
                                portrait_Ypos = headerSpacing

                                xPos = 20
                                CELL_WIDTH = (Double(UIScreen.main.bounds.width)) - 40

                            }
                            else
                            {
                                portrait_Ypos = portrait_Ypos + CELL_HEIGHT + verticalSpaing
                            }
                        }

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

                        xPos = (Double(UIScreen.main.bounds.width) - CELL_WIDTH) / 2.0
                        CELL_WIDTH = 100.0

                        if section == 0 && item == 0 {
                            cellAttributes.zIndex = 4
                        } else if section == 0 {
                            cellAttributes.zIndex = 3
                        } else if item == 0 {
                            cellAttributes.zIndex = 2
                        } else {
                            cellAttributes.zIndex = 1
                        }
                        cellAttrsDictionary[cellIndex] = cellAttributes

                    }

                }

            }
        }

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

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



}

Dont Add header for Section 0

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

    var attributesInRect = [UICollectionViewLayoutAttributes]()

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

            attributesInRect.append(cellAttributes)

            let celIndPth = cellAttributes.indexPath

            if celIndPth.section != 0
            {
                if celIndPth.item == 0
                {
                    if let supplementaryAttributes = layoutAttributesForSupplementaryView(ofKind: UICollectionElementKindSectionHeader, at: cellAttributes.indexPath) {
                        attributesInRect.append(supplementaryAttributes)
                    }

                }
            }

        }
    }

    return attributesInRect
}

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

    return cellAttrsDictionary[indexPath]!

}

Cell For Item

 override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier:  "Cell", for: indexPath) as! RulesCollectionViewCell
    cell.backgroundColor = UIColor.clear

    cell.layer.borderColor = UIColor(red: 83/255, green: 50/255, blue: 129/255, alpha: 1.0).cgColor
    cell.layer.borderWidth = 1.0
    cell.txtLbl.text = values[indexPath.section][indexPath.row]
    cell.txtLbl.textAlignment = .center
    cell.txtLbl.textColor = UIColor.white


    if indexPath.section == 0 && indexPath.row == 0
    {
        cell.backgroundColor = UIColor.white
        cell.txtLbl.textColor = UIColor.red
    }


    cell.layer.cornerRadius = 5

    cell.alpha = 1.0
    return cell
}

Array Declaration

let values = [["Main Header"],["a","b","c","d","e","f"], ["a","b","c"], ["a","b","c","d"], ["a","b","c","d","e","f"]]

Output