По какой-то причине мой код представления коллекции работает, как и ожидалось, когда я запускаю эмулятор, но когда я нажимаю кнопку «Домой», чтобы закрыть приложение и затем снова открыть его, 3 столбца свернуты справа на один столбец. Единственное, что у меня есть в раскадровке - это вид. Все делается с помощью кода. Xcode 11.1 / Swift 5.
Вот как это выглядит при первом открытии:
И при повторном открытии:
Вот весь код.
class Online: UIViewController {
weak var collectionView: UICollectionView!
var onlineArray = [[String:AnyObject]]()
override func viewDidLoad() {
super.viewDidLoad()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
collectionView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(collectionView)
NSLayoutConstraint.activate([
self.view.topAnchor.constraint(equalTo: collectionView.topAnchor),
self.view.bottomAnchor.constraint(equalTo: collectionView.bottomAnchor),
self.view.leadingAnchor.constraint(equalTo: collectionView.leadingAnchor),
self.view.trailingAnchor.constraint(equalTo: collectionView.trailingAnchor),
])
self.collectionView = collectionView
self.collectionView.dataSource = self
self.collectionView.delegate = self
self.collectionView.register(Cell.self, forCellWithReuseIdentifier: Cell.identifier)
self.collectionView.alwaysBounceVertical = true
}
}
extension Online: UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: Cell.identifier, for: indexPath) as! Cell
cell.textLabel1.text = "A"
cell.textLabel2.text = "B"
cell.textLabel3.text = "C"
cell.textLabel1.backgroundColor = .orange
cell.textLabel2.backgroundColor = .blue
cell.textLabel3.backgroundColor = .green
return cell
}
}
extension Online: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: collectionView.bounds.width, height: 30)
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) //.zero
}
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
}
}
class Cell: UICollectionViewCell {
static var identifier: String = "Cell"
weak var textLabel1: UILabel!
weak var textLabel2: UILabel!
weak var textLabel3: UILabel!
override init(frame: CGRect) {
super.init(frame: frame)
let width = self.contentView.frame.size.width
let textLabel1 = UILabel(frame: CGRect(x: 10, y: 0, width: 50, height: 20))
let textLabel2 = UILabel(frame: CGRect(x: width/3, y: 0, width: 50, height: 20))
let textLabel3 = UILabel(frame: CGRect(x: (width/3)*2, y: 0, width: 50, height: 20))
textLabel1.translatesAutoresizingMaskIntoConstraints = false
textLabel2.translatesAutoresizingMaskIntoConstraints = false
textLabel3.translatesAutoresizingMaskIntoConstraints = false
self.contentView.addSubview(textLabel1)
self.contentView.addSubview(textLabel2)
self.contentView.addSubview(textLabel3)
self.textLabel1 = textLabel1
self.textLabel2 = textLabel2
self.textLabel3 = textLabel3
self.reset()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func prepareForReuse() {
super.prepareForReuse()
self.reset()
}
func reset() {
self.textLabel1.textAlignment = .left
self.textLabel2.textAlignment = .center
self.textLabel3.textAlignment = .right
}
}