109

我刚开始学习 UICollectionViews。我想知道是否有人知道如何指定collectionview 中的列数。默认设置为 3（iPhone/纵向）。我查看了文档，似乎找不到简明的答案。

4

17 回答 17

173

在 Swift 5 和 iOS 12.3 中，您可以使用以下 4 种实现之一来设置每行中的项目数，UICollectionView同时管理插入和大小更改（包括旋转）。

#1。子类化UICollectionViewFlowLayout和使用UICollectionViewFlowLayout的itemSize属性

ColumnFlowLayout.swift：

import UIKit

class ColumnFlowLayout: UICollectionViewFlowLayout {

    let cellsPerRow: Int

    init(cellsPerRow: Int, minimumInteritemSpacing: CGFloat = 0, minimumLineSpacing: CGFloat = 0, sectionInset: UIEdgeInsets = .zero) {
        self.cellsPerRow = cellsPerRow
        super.init()

        self.minimumInteritemSpacing = minimumInteritemSpacing
        self.minimumLineSpacing = minimumLineSpacing
        self.sectionInset = sectionInset
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func prepare() {
        super.prepare()

        guard let collectionView = collectionView else { return }
        let marginsAndInsets = sectionInset.left + sectionInset.right + collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
        let itemWidth = ((collectionView.bounds.size.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
        itemSize = CGSize(width: itemWidth, height: itemWidth)
    }

    override func invalidationContext(forBoundsChange newBounds: CGRect) -> UICollectionViewLayoutInvalidationContext {
        let context = super.invalidationContext(forBoundsChange: newBounds) as! UICollectionViewFlowLayoutInvalidationContext
        context.invalidateFlowLayoutDelegateMetrics = newBounds.size != collectionView?.bounds.size
        return context
    }

}

CollectionViewController.swift：

import UIKit

class CollectionViewController: UICollectionViewController {

    let columnLayout = ColumnFlowLayout(
        cellsPerRow: 5,
        minimumInteritemSpacing: 10,
        minimumLineSpacing: 10,
        sectionInset: UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
    )

    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView?.collectionViewLayout = columnLayout
        collectionView?.contentInsetAdjustmentBehavior = .always
        collectionView?.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 59
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
        cell.backgroundColor = UIColor.orange
        return cell
    }

}

在此处输入图像描述

#2。使用UICollectionViewFlowLayout'sitemSize方法

import UIKit

class CollectionViewController: UICollectionViewController {

    let margin: CGFloat = 10
    let cellsPerRow = 5

    override func viewDidLoad() {
        super.viewDidLoad()

        guard let collectionView = collectionView, let flowLayout = collectionViewLayout as? UICollectionViewFlowLayout else { return }

        flowLayout.minimumInteritemSpacing = margin
        flowLayout.minimumLineSpacing = margin
        flowLayout.sectionInset = UIEdgeInsets(top: margin, left: margin, bottom: margin, right: margin)

        collectionView.contentInsetAdjustmentBehavior = .always
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
    }

    override func viewWillLayoutSubviews() {
        guard let collectionView = collectionView, let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout else { return }
        let marginsAndInsets = flowLayout.sectionInset.left + flowLayout.sectionInset.right + collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + flowLayout.minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
        let itemWidth = ((collectionView.bounds.size.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
        flowLayout.itemSize =  CGSize(width: itemWidth, height: itemWidth)
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 59
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
        cell.backgroundColor = UIColor.orange
        return cell
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        collectionView?.collectionViewLayout.invalidateLayout()
        super.viewWillTransition(to: size, with: coordinator)
    }

}

#3。使用UICollectionViewDelegateFlowLayout'scollectionView(_:layout:sizeForItemAt:)方法

import UIKit

class CollectionViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {

    let inset: CGFloat = 10
    let minimumLineSpacing: CGFloat = 10
    let minimumInteritemSpacing: CGFloat = 10
    let cellsPerRow = 5

    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView?.contentInsetAdjustmentBehavior = .always
        collectionView?.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
        return UIEdgeInsets(top: inset, left: inset, bottom: inset, right: inset)
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return minimumLineSpacing
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
        return minimumInteritemSpacing
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let marginsAndInsets = inset * 2 + collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
        let itemWidth = ((collectionView.bounds.size.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
        return CGSize(width: itemWidth, height: itemWidth)
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 59
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
        cell.backgroundColor = UIColor.orange
        return cell
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        collectionView?.collectionViewLayout.invalidateLayout()
        super.viewWillTransition(to: size, with: coordinator)
    }

}

#4。子类化UICollectionViewFlowLayout和使用UICollectionViewFlowLayout的estimatedItemSize属性

CollectionViewController.swift：

import UIKit

class CollectionViewController: UICollectionViewController {

    let items = [
        "Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
        "Lorem ipsum dolor sit amet, consectetur.",
        "Lorem ipsum dolor sit amet.",
        "Lorem ipsum dolor sit amet, consectetur.",
        "Lorem ipsum dolor sit amet, consectetur adipiscing.",
        "Lorem ipsum.",
        "Lorem ipsum dolor sit amet.",
        "Lorem ipsum dolor sit.",
        "Lorem ipsum dolor sit amet, consectetur adipiscing.",
        "Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
        "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.",
        "Lorem ipsum dolor sit amet, consectetur."
    ]

    let columnLayout = FlowLayout(
        cellsPerRow: 3,
        minimumInteritemSpacing: 10,
        minimumLineSpacing: 10,
        sectionInset: UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
    )

    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView?.collectionViewLayout = columnLayout
        collectionView?.contentInsetAdjustmentBehavior = .always
        collectionView?.register(Cell.self, forCellWithReuseIdentifier: "Cell")
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return items.count
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! Cell
        cell.label.text = items[indexPath.row]
        return cell
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        collectionView?.collectionViewLayout.invalidateLayout()
        super.viewWillTransition(to: size, with: coordinator)
    }

}

FlowLayout.swift：

import UIKit

class FlowLayout: UICollectionViewFlowLayout {

    let cellsPerRow: Int

    required init(cellsPerRow: Int = 1, minimumInteritemSpacing: CGFloat = 0, minimumLineSpacing: CGFloat = 0, sectionInset: UIEdgeInsets = .zero) {
        self.cellsPerRow = cellsPerRow

        super.init()

        self.minimumInteritemSpacing = minimumInteritemSpacing
        self.minimumLineSpacing = minimumLineSpacing
        self.sectionInset = sectionInset
        estimatedItemSize = UICollectionViewFlowLayout.automaticSize
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
        guard let layoutAttributes = super.layoutAttributesForItem(at: indexPath) else { return nil }
        guard let collectionView = collectionView else { return layoutAttributes }

        let marginsAndInsets = collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + sectionInset.left + sectionInset.right + minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
        layoutAttributes.bounds.size.width = ((collectionView.bounds.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)

        return layoutAttributes
    }

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        let superLayoutAttributes = super.layoutAttributesForElements(in: rect)!.map { $0.copy() as! UICollectionViewLayoutAttributes }
        guard scrollDirection == .vertical else { return superLayoutAttributes }

        let layoutAttributes = superLayoutAttributes.compactMap { layoutAttribute in
            return layoutAttribute.representedElementCategory == .cell ? layoutAttributesForItem(at: layoutAttribute.indexPath) : layoutAttribute
        }

        // (optional) Uncomment to top align cells that are on the same line
        /*
        let cellAttributes = layoutAttributes.filter({ $0.representedElementCategory == .cell })
        for (_, attributes) in Dictionary(grouping: cellAttributes, by: { ($0.center.y / 10).rounded(.up) * 10 }) {
            guard let max = attributes.max(by: { $0.size.height < $1.size.height }) else { continue }
            for attribute in attributes where attribute.size.height != max.size.height {
                attribute.frame.origin.y = max.frame.origin.y
            }
        }
         */

        // (optional) Uncomment to bottom align cells that are on the same line
        /*
        let cellAttributes = layoutAttributes.filter({ $0.representedElementCategory == .cell })
        for (_, attributes) in Dictionary(grouping: cellAttributes, by: { ($0.center.y / 10).rounded(.up) * 10 }) {
            guard let max = attributes.max(by: { $0.size.height < $1.size.height }) else { continue }
            for attribute in attributes where attribute.size.height != max.size.height {
                attribute.frame.origin.y += max.frame.maxY - attribute.frame.maxY
            }
        }
         */

        return layoutAttributes
    }

}

细胞.swift：

import UIKit

class Cell: UICollectionViewCell {

    let label = UILabel()

    override init(frame: CGRect) {
        super.init(frame: frame)

        label.numberOfLines = 0
        backgroundColor = .orange
        contentView.addSubview(label)

        label.translatesAutoresizingMaskIntoConstraints = false
        label.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor).isActive = true
        label.leadingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leadingAnchor).isActive = true
        label.trailingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.trailingAnchor).isActive = true
        label.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor).isActive = true
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
        layoutIfNeeded()
        label.preferredMaxLayoutWidth = label.bounds.size.width
        layoutAttributes.bounds.size.height = contentView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
        return layoutAttributes
    }

    // Alternative implementation
    /*
    override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
        label.preferredMaxLayoutWidth = layoutAttributes.size.width - contentView.layoutMargins.left - contentView.layoutMargins.right
        layoutAttributes.bounds.size.height = contentView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
        return layoutAttributes
    }
    */

}

在此处输入图像描述

于 2016-12-31T15:32:51.593 回答
84

CollectionViews 非常强大，而且它们是有代价的。很多，还有很多选择。正如 omz 所说：

有多种方法可以更改列数

我建议实施<UICollectionViewDelegateFlowLayout>协议，让您可以访问以下方法，您可以更好地控制您的布局UICollectionView，而无需对其进行子类化：

  • collectionView:layout:insetForSectionAtIndex:
  • collectionView:layout:minimumInteritemSpacingForSectionAtIndex:
  • collectionView:layout:minimumLineSpacingForSectionAtIndex:
  • collectionView:layout:referenceSizeForFooterInSection:
  • collectionView:layout:referenceSizeForHeaderInSection:
  • collectionView:layout:sizeForItemAtIndexPath:

此外，实现以下方法将强制您的 UICollectionView 在方向更改时更新其布局：（假设您想重新调整横向单元格的大小并使其拉伸）

-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
                               duration:(NSTimeInterval)duration{

    [self.myCollectionView.collectionViewLayout invalidateLayout];
}

此外，这里有 2 个非常好的教程UICollectionViews：

http://www.raywenderlich.com/22324/beginning-uicollectionview-in-ios-6-part-12

http://skeuo.com/uicollectionview-custom-layout-tutorial

于 2013-02-03T17:38:23.527 回答
62

我UICollectionViewDelegateFlowLayout在 my 上实现UICollectionViewController并覆盖了负责确定 Cell 大小的方法。然后我将屏幕宽度与我的列要求分开。例如，我想在每个屏幕尺寸上有 3 列。所以这就是我的代码的样子 -

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout *)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    CGFloat screenWidth = screenRect.size.width;
    float cellWidth = screenWidth / 3.0; //Replace the divisor with the column count requirement. Make sure to have it in float.
    CGSize size = CGSizeMake(cellWidth, cellWidth);

    return size;
}
于 2015-10-17T18:34:41.460 回答
43

扩展菜鸟的答案：

func collectionView(collectionView: UICollectionView,
    layout collectionViewLayout: UICollectionViewLayout,
    sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

        let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
        let totalSpace = flowLayout.sectionInset.left
            + flowLayout.sectionInset.right
            + (flowLayout.minimumInteritemSpacing * CGFloat(numberOfItemsPerRow - 1))
        let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(numberOfItemsPerRow))
        return CGSize(width: size, height: size)
}

这允许单元格之间的任何间距。它假定一个Int名为的成员变量numberOfItemsPerRow，并且所有单元格都是正方形且大小相同。正如 jhilgert00 的回答中所述，我们还必须对方向变化做出反应，但现在使用viewWillTransitionToSizeaswillRotateToInterfaceOrientation已贬值。

于 2016-03-06T12:35:19.670 回答
16

这是 Swift 3 或更高版本的工作代码，具有两列布局：

func collectionView(_ collectionView: UICollectionView,
                    layout collectionViewLayout: UICollectionViewLayout,
                    sizeForItemAt indexPath: IndexPath) -> CGSize {
    
    let nbCol = 2
    
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let totalSpace = flowLayout.sectionInset.left
        + flowLayout.sectionInset.right
        + (flowLayout.minimumInteritemSpacing * CGFloat(nbCol - 1))
    let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(nbCol))
    return CGSize(width: size, height: size)
}

随意将“nbCol”更改为您想要的列数。

于 2016-10-17T14:28:09.970 回答
11

更新到 Swift 5+ iOS 13

Collectionview Estimate Size 必须为none

在此处输入图像描述

声明单元格的边距

let margin: CGFloat = 10

在 viewDidLoad 中配置minimumInteritemSpacing, minimumLineSpacing,sectionInset

 guard let collectionView = docsColl, let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout else { return }

    flowLayout.minimumInteritemSpacing = margin
    flowLayout.minimumLineSpacing = margin
    flowLayout.sectionInset = UIEdgeInsets(top: margin, left: margin, bottom: margin, right: margin)

UICollectionViewDataSource方法sizeForItemAt

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

    let noOfCellsInRow = 2   //number of column you want
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let totalSpace = flowLayout.sectionInset.left
        + flowLayout.sectionInset.right
        + (flowLayout.minimumInteritemSpacing * CGFloat(noOfCellsInRow - 1))

    let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(noOfCellsInRow))
    return CGSize(width: size, height: size)
}
于 2020-02-28T07:29:41.020 回答
8

如果你懒惰使用委托。

extension UICollectionView {
    func setItemsInRow(items: Int) {
        if let layout = self.collectionViewLayout as? UICollectionViewFlowLayout {
            let contentInset = self.contentInset
            let itemsInRow: CGFloat = CGFloat(items);
            let innerSpace = layout.minimumInteritemSpacing * (itemsInRow - 1.0)
            let insetSpace = contentInset.left + contentInset.right + layout.sectionInset.left + layout.sectionInset.right
            let width = floor((CGRectGetWidth(frame) - insetSpace - innerSpace) / itemsInRow);
            layout.itemSize = CGSizeMake(width, width)
        }
    }
}

PS：也应该在轮换后调用

于 2016-06-08T08:51:23.180 回答
8

更新到 Swift 3：

而不是流布局，我更喜欢为特定的列号和行号使用自定义布局。因为：

  1. 如果列数很大，可以水平拖动。
  2. 由于使用列和行，它在逻辑上更容易接受。

普通单元格和标题单元格：（将 UILabel 作为 IBOutlet 添加到您的 xib）：

class CollectionViewCell: UICollectionViewCell {

@IBOutlet weak var label: UILabel!

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
    self.backgroundColor = UIColor.black
    label.textColor = UIColor.white
}
}

class CollectionViewHeadCell: UICollectionViewCell {

@IBOutlet weak var label: UILabel!

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
    self.backgroundColor = UIColor.darkGray
    label.textColor = UIColor.white
}
}

自定义布局：

let cellHeight: CGFloat = 100
let cellWidth: CGFloat = 100

class CustomCollectionViewLayout: UICollectionViewLayout {
    private var numberOfColumns: Int!
    private var numberOfRows: Int!

    // It is two dimension array of itemAttributes
    private var itemAttributes = [[UICollectionViewLayoutAttributes]]()
    // It is one dimension of itemAttributes
    private var cache = [UICollectionViewLayoutAttributes]()

override func prepare() {
    if self.cache.isEmpty {

        self.numberOfColumns = self.collectionView?.numberOfItems(inSection: 0)
        self.numberOfRows = self.collectionView?.numberOfSections

        // Dynamically change cellWidth if total cell width is smaller than whole bounds
        /* if (self.collectionView?.bounds.size.width)!/CGFloat(self.numberOfColumns) > cellWidth {
         self.cellWidth = (self.collectionView?.bounds.size.width)!/CGFloat(self.numberOfColumns)
         }
         */
        for row in 0..<self.numberOfRows {
            var row_temp = [UICollectionViewLayoutAttributes]()
            for column in 0..<self.numberOfColumns {

                let indexPath = NSIndexPath(item: column, section: row)

                let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath as IndexPath)
                attributes.frame = CGRect(x: cellWidth*CGFloat(column), y: cellHeight*CGFloat(row), width: cellWidth, height: cellHeight)

                row_temp.append(attributes)

                self.cache.append(attributes)
            }
            self.itemAttributes.append(row_temp)
        }
    }
}
override var collectionViewContentSize: CGSize {
    return CGSize(width: CGFloat(self.numberOfColumns)*cellWidth, height: CGFloat(self.numberOfRows)*cellHeight)
}

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

    var layoutAttributes = [UICollectionViewLayoutAttributes]()

    for attributes in cache {
        if attributes.frame.intersects(rect) {
            layoutAttributes.append(attributes)
        }
    }
    return layoutAttributes
}
}

集合视图：

let CellIdentifier = "CellIdentifier"
let HeadCellIdentifier = "HeadCellIdentifier"

class CollectionView: UICollectionView, UICollectionViewDelegate, UICollectionViewDataSource {

init() {
    let layout = CustomCollectionViewLayout()

    super.init(frame: CGRect.zero, collectionViewLayout: layout)

    self.register(UINib(nibName: "CollectionViewCell", bundle: nil), forCellWithReuseIdentifier: CellIdentifier)
    self.register(UINib(nibName: "CollectionViewHeadCell", bundle: nil), forCellWithReuseIdentifier: HeadCellIdentifier)

    self.isDirectionalLockEnabled = true
    self.dataSource = self
    self.delegate = self
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

func updateCollectionView() {
    DispatchQueue.main.async {
        self.reloadData()
    }
}

// MARK: CollectionView datasource
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 20
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
    return 20
}
override func numberOfItems(inSection section: Int) -> Int {
    return 20
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let column = (indexPath as NSIndexPath).row
    let row = (indexPath as NSIndexPath).section

    if column == 0 {
        let cell : CollectionViewHeadCell = collectionView.dequeueReusableCell(withReuseIdentifier: HeadCellIdentifier, for: indexPath) as! CollectionViewHeadCell

        cell.label.text = "\(row)"

        return cell
    }
    else if row == 0 {
        let cell : CollectionViewHeadCell = collectionView.dequeueReusableCell(withReuseIdentifier: HeadCellIdentifier, for: indexPath) as! CollectionViewHeadCell

        cell.label.text = "\(column)"

        return cell
    }
    else {
        let cell : CollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: CellIdentifier, for: indexPath) as! CollectionViewCell

        cell.label.text = String(format: "%d", arguments: [indexPath.section*indexPath.row])

        return cell
    }
}

// MARK: CollectionView delegate
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

    let column = (indexPath as NSIndexPath).row
    let row = (indexPath as NSIndexPath).section

    print("\(column)  \(row)")
}
}

使用 ViewController 中的 CollectionView：

class ViewController: UIViewController {
let collectionView = CollectionView()

override func viewDidLoad() {
    collectionView.translatesAutoresizingMaskIntoConstraints = false
    self.view.addSubview(collectionView)
    self.view.backgroundColor = UIColor.red

    self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[collectionView]|", options: [], metrics: nil, views: ["collectionView": collectionView]))
    self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[collectionView]|", options: [], metrics: nil, views: ["collectionView": collectionView]))
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    collectionView.updateCollectionView()
}
}

最后你可以拥有精美的 CollectionView！

在此处输入图像描述

于 2016-02-12T12:35:47.687 回答
7

因为UICollectionView非常灵活，有多种方法可以更改列数，具体取决于您使用的布局类型。

（这UICollectionViewFlowLayout可能是您正在使用的）没有直接指定列数（因为它取决于视图大小/方向）。更改它的最简单方法是设置itemSize属性和/或minimumInteritemSpacing/ minimumLineSpacing。

于 2013-02-03T17:18:36.283 回答
5

斯威夫特 3.0。适用于水平和垂直滚动方向和可变间距

指定列数

let numberOfColumns: CGFloat = 3

配置flowLayout为渲染指定numberOfColumns

if let flowLayout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout {
    let horizontalSpacing = flowLayout.scrollDirection == .vertical ? flowLayout.minimumInteritemSpacing : flowLayout.minimumLineSpacing
    let cellWidth = (collectionView.frame.width - max(0, numberOfColumns - 1)*horizontalSpacing)/numberOfColumns
    flowLayout.itemSize = CGSize(width: cellWidth, height: cellWidth)
}
于 2017-05-31T20:35:10.187 回答
2

它全都与您要绘制的布局有关。您可以创建从 UICollectionViewFlowLayout 继承的自定义类。目前没有任何直接的方法来设置列。如果你想实现这种功能，你需要手动完成。您需要在自定义流布局类中处理它。

现在将出现问题，您将如何做到这一点？如果您不想打扰单元格框架，您可以调整

 collectionView:layout:minimumInteritemSpacingForSectionAtIndex:
 collectionView:layout:minimumLineSpacingForSectionAtIndex:

另一种方法是为您提供自己的单元格位置。通过覆盖以下两种方法，它们将在您的布局形成期间被调用。

  - (NSArray*)layoutAttributesForElementsInRect:(CGRect)rect
  - (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)path

UICollectionViewLayoutAttributes 是处理单元格位置、框架、Zindex 等的类

于 2013-02-05T10:09:38.230 回答
2

首先添加UICollectionViewDelegateFlowLayout作为协议。

然后：

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
{
        var columnCount = 3
        let width  = (view.frame.width - 20) / columnCount
        return CGSize(width: width, height: width)
}
于 2020-03-18T13:53:35.170 回答
2

这个答案适用于 swift 3.0 -->

首先符合协议：

 UICollectionViewDelegateFlowLayout

然后添加这些方法：

    //this method is for the size of items      
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let width = collectionView.frame.width/3
        let height : CGFloat = 160.0
        return CGSize(width: width, height: height)
    }
    //these methods are to configure the spacing between items

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

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
        return 0
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return 0
    }
于 2017-12-14T16:41:45.503 回答
1

我只是想附加到 Imanou Petit 的答案 #2。为了确保无论屏幕宽度如何，边距都是准确的，我使用具有所需边距的迭代求解器，并将列数作为输入。我还添加了一个方向标志，用于将它们的最终边距与目标进行比较。

迭代求解器如下所示，并返回 cellWidth 和 margin。

private func iterativeCellSpacing(targetMargins : CGFloat,
                                  cellsPerRow : Int,
                                  isMinTarget : Bool) -> (CGFloat, CGFloat)
{
    var w : CGFloat = 0
    var m : CGFloat = targetMargins
    let cols : CGFloat = CGFloat(cellsPerRow)

    let numMargins : CGFloat = cols + 1.0
    let screenWidth : CGFloat = collectionView!.bounds.size.width


    var delta = CGFloat.greatestFiniteMagnitude
    while abs(delta) > 0.001
    {
        let totalMarginSpacing = numMargins * m
        let totalCellSpacing = screenWidth - totalMarginSpacing

        if (isMinTarget)
        {
            w = floor(totalCellSpacing / cols)
            m = ceil((screenWidth - cols * w) / numMargins)
        }
        else
        {
            w = ceil(totalCellSpacing / cols)
            m = floor((screenWidth - cols * w) / numMargins)
        }

        delta = screenWidth - w * CGFloat(cellsPerRow) - m * numMargins
    }

    return (w, m)
}

我这样称呼它：

fileprivate var margin: CGFloat = 20
fileprivate var cellWidth : CGFloat = 80
fileprivate let cellsPerRow = 4

override func viewDidLoad()
{
    super.viewDidLoad()

    (cellWidth, margin) = iterativeCellSpacing(targetMargins: margin, cellsPerRow: 4, isMinTarget: true)
    ...
}

然后，我将 cellWidth 和边距值应用于流布局，如下所示：

extension MyCollectionController : UICollectionViewDelegateFlowLayout

{ func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize { return CGSize(width: cellWidth, height: cellWidth) }

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    collectionView?.collectionViewLayout.invalidateLayout()
    super.viewWillTransition(to: size, with: coordinator)
}

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

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat
{
    return margin
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat
{
    return margin
}

}

希望这可以帮助。可能有一种更简单的方法可以确保边距准确，但这是一种方法。此外，此代码尚未针对允许旋转集合视图的设备进行测试。

谢谢，

于 2017-10-17T06:40:59.207 回答
0

我做了一个集合布局。

要使分隔符可见，请将集合视图的背景颜色设置为灰色。每节一排。

用途：

let layout = GridCollectionViewLayout()
layout.cellHeight = 50 // if not set, cellHeight = Collection.height/numberOfSections
layout.cellWidth = 50  // if not set, cellWidth = Collection.width/numberOfItems(inSection)
collectionView.collectionViewLayout = layout

布局：

import UIKit

class GridCollectionViewLayout: UICollectionViewLayout {


var cellWidth : CGFloat = 0
var cellHeight : CGFloat = 0
var seperator: CGFloat = 1

private var cache = [UICollectionViewLayoutAttributes]()



override func prepare() {

    guard let collectionView = self.collectionView else {
        return
    }

    self.cache.removeAll()



        let numberOfSections = collectionView.numberOfSections

        if cellHeight <= 0
        {
            cellHeight = (collectionView.bounds.height - seperator*CGFloat(numberOfSections-1))/CGFloat(numberOfSections)
        }

        for section in 0..<collectionView.numberOfSections {

            let numberOfItems = collectionView.numberOfItems(inSection: section)

            let cellWidth2 : CGFloat
            if cellWidth <= 0
            {
                cellWidth2 = (collectionView.bounds.width - seperator*CGFloat(numberOfItems-1))/CGFloat(numberOfItems)
            }
            else
            {
                cellWidth2 = cellWidth
            }


            for row in 0..<numberOfItems {


                let indexPath = NSIndexPath(row: row, section: section)

                let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath as IndexPath)
                attributes.frame = CGRect(x: (cellWidth2+seperator)*CGFloat(row),
                                          y: (cellHeight+seperator)*CGFloat(section),
                                          width: cellWidth2,
                                          height: cellHeight)

                //row_temp.append(attributes)

                self.cache.append(attributes)
            }
            //self.itemAttributes.append(row_temp)
        }

}

override var collectionViewContentSize: CGSize {

    guard let collectionView = collectionView else
    {
        return CGSize.zero
    }

    if (collectionView.numberOfSections <= 0)
    {
        return collectionView.bounds.size
    }

    let width:CGFloat
    if cellWidth <= 0
    {
        width = collectionView.bounds.width
    }
    else
    {
        width = cellWidth*CGFloat(collectionView.numberOfItems(inSection: 0))
    }

    let numberOfSections = CGFloat(collectionView.numberOfSections)
    var height:CGFloat = 0
    height += numberOfSections * cellHeight
    height += (numberOfSections - 1) * seperator



    return CGSize(width: width, height: height)
}

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

    var layoutAttributes = [UICollectionViewLayoutAttributes]()

    for attributes in cache {
        if attributes.frame.intersects(rect) {
            layoutAttributes.append(attributes)
        }
    }
    return layoutAttributes
}

override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
    return cache[indexPath.item]
}
}
于 2017-12-05T02:27:59.887 回答
0

完美的解决方案是使用 UICollectionViewDelegateFlowLayout 但是你可以很容易地计算单元格宽度并划分你想要的列数

棘手的是使宽度没有分数

(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath

{
 CGFloat screenWidth = self.view.frame.size.width;
   CGFloat marginWidth = (screenWidth - collectionView.frame.size.width);


   CGFloat cellWith = (collectionView.frame.size.width - marginWidth )/3;
   cellWith= floorf(cellWith);




  CGSize retval = CGSizeMake(cellWith,cellWith);


  return retval;}
于 2017-04-19T13:40:02.357 回答
0

试试这个，它对我来说很完美，

请按照以下步骤操作：

1. 在 .h 文件中定义值。

     #define kNoOfColumsForCollection 3
     #define kNoOfRowsForCollection 4
     #define kcellSpace 5
     #define kCollectionViewCellWidth (self.view.frame.size.width - kcellSpace*kNoOfColumsForCollection)/kNoOfColumsForCollection
     #define kCollectionViewCellHieght (self.view.frame.size.height-40- kcellSpace*kNoOfRowsForCollection)/kNoOfRowsForCollection

或者

  #define kNoOfColumsForCollection 3
  #define kCollectionViewCellWidthHieght (self.view.frame.size.width - 6*kNoOfColumsForCollection)/kNoOfColumsForCollection

2.在集合视图布局数据源方法中添加代码如下，

 #pragma mark Collection View Layout data source methods
// collection view with autolayout

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
return 4;
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
 {
 return 1;
}

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
return UIEdgeInsetsMake(4, 4, 4, 4);
}
- (CGSize)collectionView:(UICollectionView *)collectionView
              layout:(UICollectionViewLayout *)collectionViewLayout
   sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
 return 
 CGSizeMake(kCollectionViewCellWidth,kCollectionViewCellHieght);
 // CGSizeMake (kCollectionViewCellWidthHieght,kCollectionViewCellWidthHieght);
}

希望这对某人有所帮助。

于 2018-02-08T09:08:10.713 回答