如何在所有设备中使用 swift4 在 CollectionView 中显示两列

Question

要在 collectionView 中仅显示两列，我正在使用这段代码

    let layout = self.collectionView.collectionViewLayout as! UICollectionViewFlowLayout
    layout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0)
    layout.minimumInteritemSpacing = 4
    layout.itemSize = CGSize(width:(self.collectionView.frame.size.width - 10)/2,height: (self.collectionView.frame.size.height)/3)

但它只能在 5s 上正确显示，而不是在每部 iphone 上。 请帮忙。

我想像这张图片一样显示我的视图控制器。 请帮助任何人

Answer 1

你一定是缺少UICollectionViewDelegateFlowLayout

试试这个，看看：

// Source code
import UIKit

class CollectionVC: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {

    @IBOutlet var collection: UICollectionView!
    override func viewDidLoad() {
        super.viewDidLoad()
        collection.delegate = self
        collection.dataSource = self
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        //collection.reloadData()
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let flowayout = collectionViewLayout as? UICollectionViewFlowLayout
        let space: CGFloat = (flowayout?.minimumInteritemSpacing ?? 0.0) + (flowayout?.sectionInset.left ?? 0.0) + (flowayout?.sectionInset.right ?? 0.0)
        let size:CGFloat = (collection.frame.size.width - space) / 2.0
        return CGSize(width: size, height: size)
    }


    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 50
    }

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

}

// 界面设计

结果：

Answer 2

确保您的协议确认您的ViewController ，

class ViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout

并将流布局设置为您的collectionview对象

在视图中加载

let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .vertical //.horizontal
layout.minimumLineSpacing = 5
layout.minimumInteritemSpacing = 5
collectionView.setCollectionViewLayout(layout, animated: true)

并实现以下方法

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    return UIEdgeInsets(top: 1.0, left: 1.0, bottom: 1.0, right: 1.0)//here your custom value for spacing
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let lay = collectionViewLayout as! UICollectionViewFlowLayout
    let widthPerItem = collectionView.frame.width / 2 - lay.minimumInteritemSpacing
    
    return CGSize(width:widthPerItem, height:100)
}

Answer 3

将此代码添加到viewDidLoad 。 根据你改变高度。

试试这个！

if let layout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout{
        layout.minimumLineSpacing = 10
        layout.minimumInteritemSpacing = 10
        layout.sectionInset = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)
        let size = CGSize(width:(collectionView!.bounds.width-30)/2, height: 250)
        layout.itemSize = size
}

Answer 4

我已经实现了以下代码以在集合视图中显示两列。

添加UICollectionViewDelegateFlowLayout的如下方法方法：

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let size = (collectionView.frame.size.width - 30) / 2
    return CGSize(width: size, height: size)
}

其中 30 代表单元格之间的左、右和中间空间。

即单元格应在左侧添加 10 个像素，在右侧添加 10 个像素，在两个单元格之间添加 10 个像素。

从情节提要和尺寸检查器中选择您的collectionview视图，并按照最小间距设置。

我希望这能解决你的问题。

如果有任何疑问，请告诉我。

Answer 5

Swift 5 和 XCode 12.4 的更新

    import UIKit

class TwoColumnViewController: UIViewController {

    enum Section {
        case main
    }

    var dataSource: UICollectionViewDiffableDataSource<Section, Int>! = nil
    var collectionView: UICollectionView! = nil

    override func viewDidLoad() {
        super.viewDidLoad()
        navigationItem.title = "Two-Column Grid"
        configureHierarchy()
        configureDataSource()
    }
}

extension TwoColumnViewController {
    /// - Tag: TwoColumn
    func createLayout() -> UICollectionViewLayout {
        let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
                                             heightDimension: .fractionalHeight(1.0))
        let item = NSCollectionLayoutItem(layoutSize: itemSize)

        let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
                                              heightDimension: .absolute(44))
        let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitem: item, count: 2)
        let spacing = CGFloat(10)
        group.interItemSpacing = .fixed(spacing)

        let section = NSCollectionLayoutSection(group: group)
        section.interGroupSpacing = spacing
        section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 10, bottom: 0, trailing: 10)

        let layout = UICollectionViewCompositionalLayout(section: section)
        return layout
    }
}

extension TwoColumnViewController {
    func configureHierarchy() {
        collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout())
        collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        collectionView.backgroundColor = .systemBackground
        view.addSubview(collectionView)
    }
    func configureDataSource() {
        let cellRegistration = UICollectionView.CellRegistration<TextCell, Int> { (cell, indexPath, identifier) in
            // Populate the cell with our item description.
            cell.label.text = "\(identifier)"
            cell.contentView.backgroundColor = .cornflowerBlue
            cell.layer.borderColor = UIColor.black.cgColor
            cell.layer.borderWidth = 1
            cell.label.textAlignment = .center
            cell.label.font = UIFont.preferredFont(forTextStyle: .title1)
        }
        
        dataSource = UICollectionViewDiffableDataSource<Section, Int>(collectionView: collectionView) {
            (collectionView: UICollectionView, indexPath: IndexPath, identifier: Int) -> UICollectionViewCell? in
            // Return the cell.
            return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: identifier)
        }

        // initial data
        var snapshot = NSDiffableDataSourceSnapshot<Section, Int>()
        snapshot.appendSections([.main])
        snapshot.appendItems(Array(0..<94))
        dataSource.apply(snapshot, animatingDifferences: false)
    }
}