尝试这种方法，在viewDidLoad中将collection isPagingEnabled设置为true

YourCollectionView.isPagingEnabled = true

在cellForItemAt中将CONTENTVIEW边框颜色设置为clear，宽度设置为0：

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    
    let cell = YourCollectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! MenuCell
    cell.contentView.backgroundColor = .red
    cell.contentView.layer.borderColor = UIColor.clear.cgColor
    cell.contentView.layer.borderWidth = 0
    
    return cell
}

现在，在didSelectItemAt中，将所有可见单元格重置为无边框，并仅选择边框：

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let cell = YourCollectionView.cellForItem(at: indexPath) as! YourCell
    // set ALL visible cell to no border
    for myCell in YourCollectionView.visibleCells {
        myCell.contentView.layer.borderColor = UIColor.clear.cgColor
        myCell.contentView.layer.borderWidth = 0
    }
    // set ONLY SELECTED CELL border to your prefer color and width
    cell.contentView.layer.borderColor = UIColor.white.cgColor
    cell.contentView.layer.borderWidth = 1
}

现在可以在scrollViewDidScroll方法中检测页面更改并重置边框：

var previousPage: Int = 0
func scrollViewDidScroll(_ scrollView: UIScrollView){
    let pageWidth: CGFloat = scrollView.frame.width
    let fractionalPage: CGFloat = scrollView.contentOffset.x / pageWidth
    let page = lround(Double(fractionalPage))
    if page != previousPage {
        // page changed
        print(page)
        // reset all cells to no border when page changed
        for myCell in YourCollectionView.visibleCells {
            myCell.contentView.layer.borderColor = UIColor.clear.cgColor
            myCell.contentView.layer.borderWidth = 0
        }
    }
}

这就是结果