수평으로 UICollectionView 셀을 중앙에 배치하는 방법은 무엇입니까?

몇 가지 연구를 수행했지만 UICollectionView에서 셀을 가로로 가운데에 배치하는 방법에 대한 코드 예제를 찾을 수 없습니다.

첫 번째 셀이 X00 과 같은 대신 과 같은 것이 아니라이 0X0 과 같기를 원합니다 . 이것을 달성하는 방법이 있습니까?

편집하다:

내가 원하는 것을 시각화하려면 :

CollectionView에 요소가 하나만있을 때 버전 B처럼 보이도록해야합니다. 요소가 두 개 이상 있으면 버전 A와 비슷하지만 요소가 더 많아야합니다.

지금은 요소가 1 개 뿐인데 버전 A처럼 보이며 어떻게 B처럼 보이게 만들 수 있는지 궁금합니다.

도와 주셔서 감사합니다!

라이브러리를 사용하는 것은 좋은 생각이 아닙니다. 만약 당신의 목적이 이것이 바로 중앙 정렬이라면.

collectionViewLayout 함수에서이 간단한 계산을 더 잘 수행 할 수 있습니다.

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {

    let totalCellWidth = CellWidth * CellCount
    let totalSpacingWidth = CellSpacing * (CellCount - 1)

    let leftInset = (collectionViewWidth - CGFloat(totalCellWidth + totalSpacingWidth)) / 2
    let rightInset = leftInset

    return UIEdgeInsets(top: 0, left: leftInset, bottom: 0, right: rightInset)
}

스위프트 5.1

func centerItemsInCollectionView(cellWidth: Double, numberOfItems: Double, spaceBetweenCell: Double, collectionView: UICollectionView) -> UIEdgeInsets {
    let totalWidth = cellWidth * numberOfItems
    let totalSpacingWidth = spaceBetweenCell * (numberOfItems - 1)
    let leftInset = (collectionView.frame.width - CGFloat(totalWidth + totalSpacingWidth)) / 2
    let rightInset = leftInset
    return UIEdgeInsets(top: 0, left: leftInset, bottom: 0, right: rightInset)
}

스위프트 4.2

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {

    let totalCellWidth = 80 * collectionView.numberOfItems(inSection: 0)
    let totalSpacingWidth = 10 * (collectionView.numberOfItems(inSection: 0) - 1)

    let leftInset = (collectionView.layer.frame.size.width - CGFloat(totalCellWidth + totalSpacingWidth)) / 2
    let rightInset = leftInset

    return UIEdgeInsets(top: 0, left: leftInset, bottom: 0, right: rightInset)

}

스위프트 3

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {

        let totalCellWidth = 80 * collectionView.numberOfItems(inSection: 0)
        let totalSpacingWidth = 10 * (collectionView.numberOfItems(inSection: 0) - 1)

        let leftInset = (collectionView.layer.frame.size.width - CGFloat(totalCellWidth + totalSpacingWidth)) / 2
        let rightInset = leftInset

        return UIEdgeInsetsMake(0, leftInset, 0, rightInset)

    }

프로토콜을 추가하는 것을 잊지 마세요

UICollectionViewDelegateFlowLayout

Swift 4에 사용해보세요

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
        let cellWidth : CGFloat = 165.0

        let numberOfCells = floor(self.view.frame.size.width / cellWidth)
        let edgeInsets = (self.view.frame.size.width - (numberOfCells * cellWidth)) / (numberOfCells + 1)

        return UIEdgeInsetsMake(15, edgeInsets, 0, edgeInsets)
    }

165.0 대신 cellWidth 추가

이를 위해 KTCenterFlowLayout 을 사용 하며 훌륭하게 작동합니다. UICollectionViewFlowLayout원하는대로 중앙 셀 의 사용자 지정 하위 클래스입니다 . (참고 : 이것은 일부 코드를 게시하여 해결하는 사소한 일이 아니기 때문에 GitHub 프로젝트에 연결합니다!)

Darshan Patel의 답변에 대한 객관적인 C 버전 :

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(nonnull UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    CGFloat totalCellWidth = kItemWidth * self.dataArray.count;
    CGFloat totalSpacingWidth = kSpacing * (((float)self.dataArray.count - 1) < 0 ? 0 :self.dataArray.count - 1);
    CGFloat leftInset = (self.bounds.size.width - (totalCellWidth + totalSpacingWidth)) / 2;
    CGFloat rightInset = leftInset;
    UIEdgeInsets sectionInset = UIEdgeInsetsMake(0, leftInset, 0, rightInset);
    return sectionInset;
}

@Safad Funy의 답변을 약간 수정하면 Swift 및 iOS의 최신 버전에서 저에게 효과적이었습니다. 이 경우 셀 너비가 컬렉션 뷰 크기의 1/3이되기를 원했습니다.

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {

  let totalCellWidth = Int(collectionView.layer.frame.size.width) / 3 * collectionView.numberOfItems(inSection: 0)
  let totalSpacingWidth = (collectionView.numberOfItems(inSection: 0) - 1)

  let leftInset = (collectionView.layer.frame.size.width - CGFloat(totalCellWidth + totalSpacingWidth)) / 2
  let rightInset = leftInset

  return UIEdgeInsetsMake(0, leftInset, 0, rightInset)
}

이 확장 프로그램 (Swift 4)을 사용할 수 있습니다.

당신 collectionView이 가지고 있다면 그것은 세포를 중심에 둘 수 있습니다layout.estimatedItemSize = UICollectionViewFlowLayoutAutomaticSize .

모든 세포 크기에서 작동하며 다음과 같은 경우 완벽하게 작동합니다. scrollDirection = .horizontal

public extension UICollectionView {
    func centerContentHorizontalyByInsetIfNeeded(minimumInset: UIEdgeInsets) {
        guard let layout = collectionViewLayout as? UICollectionViewFlowLayout,
            layout.scrollDirection == .horizontal else {
                assertionFailure("\(#function): layout.scrollDirection != .horizontal")
                return
        }

        if layout.collectionViewContentSize.width > frame.size.width {
            contentInset = minimumInset
        } else {
            contentInset = UIEdgeInsets(top: minimumInset.top,
                                        left: (frame.size.width - layout.collectionViewContentSize.width) / 2,
                                        bottom: minimumInset.bottom,
                                        right: 0)
        }
    }
}


final class Foo: UIViewController {
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        collectionView.centerContentHorizontalyByInsetIfNeeded(minimumInset: yourDefaultInset)
    }
}

도움이되기를 바랍니다!

Swift 4.2 (수평 및 수직). Pink Panther 코드의 작은 업그레이드이며 그에게 큰 감사를드립니다!

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let cellWidth: CGFloat = flowLayout.itemSize.width
    let cellHieght: CGFloat = flowLayout.itemSize.height
    let cellSpacing: CGFloat = flowLayout.minimumInteritemSpacing
    let cellCount = CGFloat(collectionView.numberOfItems(inSection: section))
    var collectionWidth = collectionView.frame.size.width
    var collectionHeight = collectionView.frame.size.height
    if #available(iOS 11.0, *) {
        collectionWidth -= collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right
        collectionHeight -= collectionView.safeAreaInsets.top + collectionView.safeAreaInsets.bottom
    }
    let totalWidth = cellWidth * cellCount + cellSpacing * (cellCount - 1)
    let totalHieght = cellHieght * cellCount + cellSpacing * (cellCount - 1)
    if totalWidth <= collectionWidth {
        let edgeInsetWidth = (collectionWidth - totalWidth) / 2

        print(edgeInsetWidth, edgeInsetWidth)
        return UIEdgeInsets(top: 5, left: edgeInsetWidth, bottom: flowLayout.sectionInset.top, right: edgeInsetWidth)
    } else {
        let edgeInsetHieght = (collectionHeight - totalHieght) / 2
        print(edgeInsetHieght, edgeInsetHieght)
        return UIEdgeInsets(top: edgeInsetHieght, left: flowLayout.sectionInset.top, bottom: edgeInsetHieght, right: flowLayout.sectionInset.top)

    }
}

클래스가 UICollectionViewDelegateFlowLayout 프로토콜을 준수하는지 확인하십시오.

다음은 셀이 둘 이상의 행일 때도 잘 작동하는 Swift 5 의 최신 버전입니다 .

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let cellWidth: CGFloat = flowLayout.itemSize.width
    let cellSpacing: CGFloat = flowLayout.minimumInteritemSpacing
    var cellCount = CGFloat(collectionView.numberOfItems(inSection: section))
    var collectionWidth = collectionView.frame.size.width
    var totalWidth: CGFloat
    if #available(iOS 11.0, *) {
        collectionWidth -= collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right
    }
    repeat {
        totalWidth = cellWidth * cellCount + cellSpacing * (cellCount - 1)
        cellCount -= 1
    } while totalWidth >= collectionWidth

    if (totalWidth > 0) {
        let edgeInset = (collectionWidth - totalWidth) / 2
        return UIEdgeInsets.init(top: flowLayout.sectionInset.top, left: edgeInset, bottom: flowLayout.sectionInset.bottom, right: edgeInset)
    } else {
        return flowLayout.sectionInset
    }
}

클래스 가 프로토콜을 준수 하는지 확인하십시오 UICollectionViewDelegateFlowLayout.

스위프트 4

extension ViewController: UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {

        let cellWidth: CGFloat = 170.0 // Your cell width

        let numberOfCells = floor(view.frame.size.width / cellWidth)
        let edgeInsets = (view.frame.size.width - (numberOfCells * cellWidth)) / (numberOfCells + 1)

        return UIEdgeInsetsMake(0, edgeInsets, 0, edgeInsets)
    }

 }

패딩 만 추가하려는 사용자 ( top, left, bottom, right ) :

프로토콜 추가 UICollectionViewDelegateFlowLayout

이 예제는 왼쪽과 오른쪽에 40으로 패딩을 표시합니다.

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {        
    return UIEdgeInsetsMake(0, 40, 0, 40)
}

SWIFT 4.2

private lazy var contentView: UICollectionView = {
        let layoutView: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
            layoutView.scrollDirection = .horizontal
            layoutView.minimumInteritemSpacing = 0
            layoutView.minimumLineSpacing = 5

        let collectionView: UICollectionView = UICollectionView(frame: .zero, collectionViewLayout: layoutView)
            collectionView.dataSource = self
            collectionView.delegate = self
            collectionView.showsHorizontalScrollIndicator = false
            collectionView.isPagingEnabled = true
            collectionView.registerCell(Cell.self)
            collectionView.backgroundColor = .clear
            collectionView.translatesAutoresizingMaskIntoConstraints = false
        return collectionView
    }()

//

extension CustomCollectionView: UICollectionViewDelegateFlowLayout {
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

        return CGSize(width: collectionView.frame.width*4/5, height: collectionView.frame.height)
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
        let cellWidth : CGFloat = collectionView.frame.width*4/5

        let numberOfCells = floor(collectionView.frame.width / cellWidth)
        let edgeInsets = (collectionView.frame.width - (numberOfCells * cellWidth)) / (numberOfCells + 1)

        return UIEdgeInsets(top: 0, left: edgeInsets, bottom: 0, right: edgeInsets)
    }
}

내 솔루션을 시도해 볼 수 있습니다.

func refreshCollectionView(_ count: Int) {
    let collectionViewHeight = collectionView.bounds.height
    let collectionViewWidth = collectionView.bounds.width
    let numberOfItemsThatCanInCollectionView = Int(collectionViewWidth / collectionViewHeight)
    if numberOfItemsThatCanInCollectionView > count {
        let totalCellWidth = collectionViewHeight * CGFloat(count)
        let totalSpacingWidth: CGFloat = CGFloat(count) * (CGFloat(count) - 1)
        // leftInset, rightInset are the global variables which I am passing to the below function
        leftInset = (collectionViewWidth - CGFloat(totalCellWidth + totalSpacingWidth)) / 2;
        rightInset = -leftInset
    } else {
        leftInset = 0.0
        rightInset = -collectionViewHeight
    }
    collectionView.reloadData()
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    return UIEdgeInsetsMake(0, leftInset, 0, rightInset)
}

허용 대답은 정답입니다하지만이 경우 totalCellWidth미만 CollectionView의 width이에 대해,하지만 단지 경비에 당신은 다음과 같이 할 수 있습니다.

if (leftInset > 0) {
     return UIEdgeInsetsMake(0, leftInset, 0, rightInset)
  } else {
     return UIEdgeInsetsMake(0, 10, 0, 10)
}

이 코드는 수정없이 Swift 4.0 에서도 수평 컬렉션 뷰를 중앙에 배치해야합니다 .

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let cellWidth: CGFloat = flowLayout.itemSize.width
    let cellSpacing: CGFloat = flowLayout.minimumInteritemSpacing
    let cellCount = CGFloat(collectionView.numberOfItems(inSection: section))
    var collectionWidth = collectionView.frame.size.width
    if #available(iOS 11.0, *) {
        collectionWidth -= collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right
    }
    let totalWidth = cellWidth * cellCount + cellSpacing * (cellCount - 1)
    if totalWidth <= collectionWidth {
        let edgeInset = (collectionWidth - totalWidth) / 2
        return UIEdgeInsetsMake(flowLayout.sectionInset.top, edgeInset, flowLayout.sectionInset.bottom, edgeInset)
    } else {
        return flowLayout.sectionInset
    }
}

클래스가 UICollectionViewDelegateFlowLayout프로토콜을 준수하는지 확인하십시오.

나는 여기서 완전히 다른 접근 방식을 취하게되었고, 언급 할 가치가 있다고 생각합니다.

컬렉션 뷰에 대한 제약 조건을 중앙에 수평으로 정렬하도록 설정했습니다. 그런 다음 너비를 지정하는 다른 제약 조건을 설정합니다. 컬렉션 뷰를 보유하는 viewController 내부에 너비 제약에 대한 콘센트 를 만들었습니다 . 그런 다음 데이터 소스가 변경되고 컬렉션 뷰를 업데이트 할 때 셀 수를 가져 와서 (매우 유사한) 계산을 수행하여 너비를 재설정합니다.

let newWidth = (items.count * cellWidth) + (items.count * cellSpacing)

그런 다음 제약 콘센트의 .constant값을 계산 결과로 설정하고 자동 레이아웃이 나머지 작업을 수행합니다.

이것은`UICollectionViewDelegateFlowLayout과 충돌 할 수 있지만 이것은 왼쪽 정렬 된 컬렉션 뷰를 만드는 데 완벽하게 작동했습니다. 대리자가 없으면 셀이 뷰의 대부분을 채울 때만 작동하는 것처럼 보입니다.

페이지가 너비보다 작 으면 페이지를 중앙에 배치하고 페이지가 더 많으면 왼쪽으로 정렬하는 플로우 레이아웃에 대한 일반적인 솔루션

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(nonnull UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    // Centering if there are fever pages
    CGSize itemSize = [(UICollectionViewFlowLayout *)collectionViewLayout itemSize];
    CGFloat spacing = [(UICollectionViewFlowLayout *)collectionViewLayout minimumLineSpacing];

    NSInteger count = [self collectionView:self numberOfItemsInSection:section];
    CGFloat totalCellWidth = itemSize.width * count;
    CGFloat totalSpacingWidth = spacing * ((count - 1) < 0 ? 0 : count - 1);
    CGFloat leftInset = (self.bounds.size.width - (totalCellWidth + totalSpacingWidth)) / 2;
    if (leftInset < 0) {
        UIEdgeInsets inset = [(UICollectionViewFlowLayout *)collectionViewLayout sectionInset];
        return inset;
    }
    CGFloat rightInset = leftInset;
    UIEdgeInsets sectionInset = UIEdgeInsetsMake(0, leftInset, 0, rightInset);
    return sectionInset;
}

Swift 버전 (ObjC에서 변환)

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    // Centering if there are fever pages
    let itemSize: CGSize? = (collectionViewLayout as? UICollectionViewFlowLayout)?.itemSize
    let spacing: CGFloat? = (collectionViewLayout as? UICollectionViewFlowLayout)?.minimumLineSpacing

    let count: Int = self.collectionView(self, numberOfItemsInSection: section)
    let totalCellWidth = (itemSize?.width ?? 0.0) * CGFloat(count)
    let totalSpacingWidth = (spacing ?? 0.0) * CGFloat(((count - 1) < 0 ? 0 : count - 1))
    let leftInset: CGFloat = (bounds.size.width - (totalCellWidth + totalSpacingWidth)) / 2
    if leftInset < 0 {
        let inset: UIEdgeInsets? = (collectionViewLayout as? UICollectionViewFlowLayout)?.sectionInset
        return inset!
    }
    let rightInset: CGFloat = leftInset
    let sectionInset = UIEdgeInsets(top: 0, left: Float(leftInset), bottom: 0, right: Float(rightInset))
    return sectionInset
}

프로젝트에서도 비슷한 상황이 발생하고 있습니다. UPCarouselFlowLayout

지원 swift 5버전 이라고 생각합니다

https://github.com/ink-spot/UPCarouselFlowLayout/blob/master/UPCarouselFlowLayout/UPCarouselFlowLayout.swift

코드 구현을 살펴보십시오.

override open func targetContentOffset(forProposedContentOffset proposedContentOffset: CGPoint, withScrollingVelocity velocity: CGPoint) -> CGPoint

가장 간단한 방법은 스토리 보드 또는 코드를 사용하여 컬렉션 뷰 추정 크기를 없음으로 설정하는 것입니다. layout.estimatedItemSize = CGSize.zero

그룹당 하나의 셀만있는 경우 a leading:및 trailing:of .flexible(0)는 셀을 가로로 가운데에 배치합니다.

item.edgeSpacing = NSCollectionLayoutEdgeSpacing(
    leading: .flexible(0), top: nil,                                                     
    trailing: .flexible(0), bottom: nil
)

프로젝트에서 그 코드를 사용했습니다. 이 방향 모두에서 수평 및 수직 collectionView을 중심 .horizontal과 .vertical부의 세트를 사용. 설정된 경우 섹션의 간격과 원래 삽입을 존중합니다. 재사용을 위해 스토리 보드에서 UICollectionViewDelegateFlowLayout검색 UIcollectionView하거나 설정 하는 데 필요한 모든 속성에 액세스 할 수 있도록 델리게이트에서 사용할 코드 입니다.

// original function of the delegate
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    // casting the layout as a UICollectionViewFlowLayout to have access to the properties of items for reusability - you could also link the real one from the storyboard with an outlet
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    // getting all the properties we need
    let itemWidth = flowLayout.itemSize.width
    let itemHeight = flowLayout.itemSize.height
    let interSpacing = flowLayout.minimumInteritemSpacing
    let lineSpacing = flowLayout.minimumLineSpacing
    // getting the size of the collectionView
    let collectionWidth = collectionView.bounds.width
    let collectionHeight = collectionView.bounds.height
    // getting the direction to choose how to align the collection
    let direction = flowLayout.scrollDirection
    // you don't want to have an item greater than the collection
    guard (itemWidth < collectionWidth && direction == .vertical) || (itemHeight < collectionHeight && direction == .horizontal) else {
        print("Really?")
        return UIEdgeInsets(top: flowLayout.sectionInset.top, left: flowLayout.sectionInset.left, bottom: flowLayout.sectionInset.bottom, right: flowLayout.sectionInset.right)
    }
    // getting the number of item in the current section
    let totalItemCount = CGFloat(collectionView.numberOfItems(inSection: section))
    // setting number of item in a row to the max number of items that can fit in a row without spacing or to the number of items in the section if less than the max
    var itemCountInRow = totalItemCount < (collectionWidth / itemWidth).rounded(.towardZero) ? totalItemCount : (collectionWidth / itemWidth).rounded(.towardZero)
    // how many max row can we have
    var countOfRow = totalItemCount < (collectionHeight / itemHeight).rounded(.towardZero) ? totalItemCount : (collectionHeight / itemHeight).rounded(.towardZero)
    // calculating the total width of row by multiplying the number of items in the row by the width of item and adding the spacing multiplied by the number of item minus one
    var totalWidthOfRow:CGFloat {
        get{
            return (itemWidth * itemCountInRow) + (interSpacing * (itemCountInRow - 1))
        }
    }
    // calculating the total height of row by multiplying the number of row by the height of item and adding the spacing multiplied by the number of row minus one
    var totalHeightOfRow:CGFloat {
        get{
            return (itemHeight * countOfRow) + (lineSpacing * (countOfRow - 1))
        }
    }
    // first we set the inset to the default
    var edgeInsetLeft = flowLayout.sectionInset.left
    var edgeInsetTop = flowLayout.sectionInset.top

    if direction == .vertical {
        // while the width of row with original margin is greater than the width of the collection we drop one item until it fits
        while totalWidthOfRow > collectionWidth || ((collectionWidth - totalWidthOfRow) / 2) < flowLayout.sectionInset.left {
            // droping an item to fit in the row
            itemCountInRow -= 1
        }
        // calculating the number of rows in collectionView by dividing the number of items by the number of items in a row
        countOfRow = (totalItemCount / (itemCountInRow)).rounded(.up)
    } else {
        itemCountInRow = (totalItemCount / countOfRow).rounded(.up)
        // while the height of row with original marginis greater than the height of the collection we drop one row until it fits
        while totalHeightOfRow >= collectionHeight  || ((collectionHeight - totalHeightOfRow) / 2) < flowLayout.sectionInset.top  {
            // droping an item to fit in the row
            countOfRow -= 1
        }
    }
    edgeInsetLeft = max(flowLayout.sectionInset.left, (collectionWidth - totalWidthOfRow) / 2)
    edgeInsetTop = max(flowLayout.sectionInset.top, (collectionHeight - totalHeightOfRow) / 2)
    // we don't specially need insets where the items are overflowing
    let edgeInsetRight = direction == .vertical ? edgeInsetLeft : flowLayout.sectionInset.right
    let edgeInsetBottom = direction == .horizontal ? edgeInsetTop : flowLayout.sectionInset.bottom
    // returning the UIEdgeInsets
    return UIEdgeInsets(top: edgeInsetTop, left: edgeInsetLeft, bottom: edgeInsetBottom, right: edgeInsetRight)
}

누군가 도움이 될 희망 - 그렇지 않은 항목 섹션 안에 섹션을 중심으로 더 많은 우리가 하위 클래스가 위해 UICollectionViewFlowLayout또는 UICollectionViewLayout애플의 모자이크 예로서.

나는 당신이 중심 셀 필요가 있다고 생각하므로 collectionView를 사용하는 대신 UITableView가 큰 도움이 될 것입니다. UIViewController를 사용하고 두 개의 UIView를 앞뒤에 배치하고 UITableView중간에 배치하십시오 .