Swift 如何在单元格之间获得更均匀的垂直距离?
我已经使用auto layout no storyboard或xib动态创建了单元格,但布局管理器似乎是 将细胞配对,使短细胞和高细胞并排排排成一行 我想要的是让细胞之间有一个统一的距离垂直堆叠,而不是大的空白。因此,左边三个连续的短细胞在高度和位置上可能与右边一个大细胞相等。换言之:所有单元格之间的垂直均匀距离Swift 如何在单元格之间获得更均匀的垂直距离?,swift,layout,autolayout,uicollectionviewcell,Swift,Layout,Autolayout,Uicollectionviewcell,我已经使用auto layout no storyboard或xib动态创建了单元格,但布局管理器似乎是 将细胞配对,使短细胞和高细胞并排排排成一行 我想要的是让细胞之间有一个统一的距离垂直堆叠,而不是大的空白。因此,左边三个连续的短细胞在高度和位置上可能与右边一个大细胞相等。换言之:所有单元格之间的垂直均匀距离 /// Everything is a side effect. Configure the cell passed in /// /// - Parameter
/// Everything is a side effect. Configure the cell passed in
///
/// - Parameters:
/// - cell: cell to format
/// - indexPath: index of cell
func formatAutolayoutCell(cell: AutoResizingTextCell, at indexPath: IndexPath) {
let event = eventsSource[indexPath.row]
cell.layer.borderColor = event.calendar.cgColor
cell.contentView.backgroundColor = UIColor(cgColor: event.calendar.cgColor).withAlphaComponent(0.1)
cell.titleLabel.text = event.title
cell.contentView.addSubview(cell.titleLabel)
cell.titleLabel.topAnchor.constraint(equalTo: cell.contentView.topAnchor).isActive = true
cell.titleLabel.widthAnchor.constraint(equalToConstant: cellWidth).isActive = true
cell.titleLabel.textColor = UIColor(cgColor: event.calendar.cgColor)
cell.titleLabel.textAlignment = .center
cell.contentView.addSubview(cell.bodyLabel)
cell.bodyLabel.text = event.notes ?? ""
cell.bodyLabel.widthAnchor.constraint(equalToConstant: cellWidth).isActive = true
cell.bodyLabel.bottomAnchor.constraint(equalTo: cell.contentView.bottomAnchor).isActive = true
cell.titleLabel.bottomAnchor.constraint(equalTo: cell.bodyLabel.topAnchor).isActive = true
}
编辑:
根据Galo Torres Sevilla的建议,我尝试使用UICollectionViewLayout。它使我更接近我的目标,但看起来单元格的数量是由列平均划分的,因此,如果最左边的列有短单元格,那么它很早就用完了单元格,左侧的底部有很多空间。似乎我可能需要按大小对单元格进行排序,以获得更好的分布
遵循
您可以将UICollectionViewFlowLayout子类化以获取所需内容
下面是它的主要代码。注:代码来自上述网站
您将无法使用autoLayout执行此操作。我的建议是,您将UICollectionViewFlowLayout子类化,并从中获得所需的布局。下面是一个可能适合您的示例。看起来很完美。如果你想把它写下来作为一个答案,你的答案不仅仅是一个链接,因为只有链接的答案是不允许的,我很乐意投票并接受它。你已经完成了一半以上。你的布局做得很好!你很快就明白了。我会在下面留下答案谢谢你的帮助!我已经深谙代码,所以我所读的是有意义的。而且我下定决心要做点什么!
import UIKit
protocol PinterestLayoutDelegate: class {
// 1. Method to ask the delegate for the height of the image
func collectionView(_ collectionView:UICollectionView, heightForPhotoAtIndexPath indexPath:IndexPath) -> CGFloat
}
class PinterestLayout: UICollectionViewLayout {
//1. Pinterest Layout Delegate
weak var delegate: PinterestLayoutDelegate!
//2. Configurable properties
fileprivate var numberOfColumns = 2
fileprivate var cellPadding: CGFloat = 6
//3. Array to keep a cache of attributes.
fileprivate var cache = [UICollectionViewLayoutAttributes]()
//4. Content height and size
fileprivate var contentHeight: CGFloat = 0
fileprivate var contentWidth: CGFloat {
guard let collectionView = collectionView else {
return 0
}
let insets = collectionView.contentInset
return collectionView.bounds.width - (insets.left + insets.right)
}
override var collectionViewContentSize: CGSize {
return CGSize(width: contentWidth, height: contentHeight)
}
override func prepare() {
// 1. Only calculate once
guard cache.isEmpty == true, let collectionView = collectionView else {
return
}
// 2. Pre-Calculates the X Offset for every column and adds an array to increment the currently max Y Offset for each column
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)
// 3. Iterates through the list of items in the first section
for item in 0 ..< collectionView.numberOfItems(inSection: 0) {
let indexPath = IndexPath(item: item, section: 0)
// 4. Asks the delegate for the height of the picture and the annotation and calculates the cell frame.
let photoHeight = delegate.collectionView(collectionView, heightForPhotoAtIndexPath: indexPath)
let height = cellPadding * 2 + photoHeight
let frame = CGRect(x: xOffset[column], y: yOffset[column], width: columnWidth, height: height)
let insetFrame = frame.insetBy(dx: cellPadding, dy: cellPadding)
// 5. Creates an UICollectionViewLayoutItem with the frame and add it to the cache
let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath)
attributes.frame = insetFrame
cache.append(attributes)
// 6. Updates the collection view content height
contentHeight = max(contentHeight, frame.maxY)
yOffset[column] = yOffset[column] + height
column = column < (numberOfColumns - 1) ? (column + 1) : 0
}
}
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
var visibleLayoutAttributes = [UICollectionViewLayoutAttributes]()
// Loop through the cache and look for items in the rect
for attributes in cache {
if attributes.frame.intersects(rect) {
visibleLayoutAttributes.append(attributes)
}
}
return visibleLayoutAttributes
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
return cache[indexPath.item]
}
}