从URL获取文本的Swift标签在滚动collectionView时正在改变大小

Question

In a CollectionView there are multiple Cells. All of them have a genreLabel with text from url. The text is getting displayed, but when I scroll in the CollectionView, some genreLabel are getting smaller, so the text is not completely displayed anymore. The function setupViews() is used to create constraints in CollectionViewCell and properties are set in the function configure() . Also there is a second problem coming with that: when the genreLabel is getting smaller, the discountLabel is disappearing too.

I tried to put the call of setupViews() in different places. When I put it in the init of CollectionViewCell the genreLabel is so small, it only shows one Letter of the text. When I put it at the end of configure() or after cell.configure() in collectionView(cellForItemAt) I get the problem I have right now.

The CollectionViewController:

class HomeController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout, HomeControllerDelegate {

    lazy var eventCollectionView: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.minimumInteritemSpacing = 25
        layout.minimumLineSpacing = 25
        let cv = UICollectionView(frame: CGRect(x: 25, y: 108, width: UIScreen.main.bounds.width - 50, height: UIScreen.main.bounds.height - 108), collectionViewLayout: layout)
        cv.dataSource = self
        cv.delegate = self
        return cv
    }()

    var homeEvents = [HomeEvent]()

    let homeCellId = "HomeCellId"

    override func viewDidLoad() {
        super.viewDidLoad()

        //Setting up the NavigationController...

        HomeModel.shared.getEvents {
            (response) in
            self.homeEvents = response.homeEvents
            self.eventCollectionView.reloadData()
        }
        eventCollectionView.register(HomeCell.self, forCellWithReuseIdentifier: homeCellId)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        imageCache.removeAllObjects()
    }

    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }

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

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        guard let cell = eventCollectionView.dequeueReusableCell(withReuseIdentifier: homeCellId, for: indexPath) as? HomeCell
            else {
                return UICollectionViewCell()
        }
        let event = homeEvents[indexPath.item]
        cell.configure(with: event)
//        cell.setupViews()
        cell.homeControllerDelegate = self
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        if view.frame.width < 415.0 {
            return CGSize(width: view.frame.width - 50, height: view.frame.width - 60)
        }
        else if view.frame.width < 828.0 {
            return CGSize(width: (view.frame.width / 2) - 50, height: (view.frame.width / 2) - 60)
        }
        else {
            return CGSize(width: (view.frame.width / 3) - 50, height: (view.frame.width / 3) - 60)
        }
    }
}

The CollectionViewCell:

class HomeCell: UICollectionViewCell {

    var themePage = false
    var banner = 0
    var gift = 0
    var teamEvent = 0
    var discount = 1

    func configure(with homeEvent: HomeEvent) {
        homeEvent.image {
            (image) in
            self.eventImageView.image = image
        }
        genreLabel.text = homeEvent.genre
        if homeEvent.teamEvent == "0" {
            teamEventLabel.isHidden = true
        }
        else {
            teamEvent = 1
            teamEventLabel.isHidden = false
        }
        if homeEvent.gift == "0" {
            giftLabel.isHidden = true
        }
        else {
            gift = 1
            giftLabel.isHidden = false
        }
        if homeEvent.discount.prefix(1) == "<" {
            let normalText = "Bis zu "
            let boldText = "" + homeEvent.discount.suffix(2) + "%"
            let normalAttributes = [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14)]
            let attributedString = NSMutableAttributedString(string: normalText, attributes: normalAttributes)
            let boldAttributes = [NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: 24)]
            let boldString = NSMutableAttributedString(string: boldText, attributes: boldAttributes)
            attributedString.append(boldString)
            variableDiscountLabel.attributedText = attributedString
            fixDiscountLabel.isHidden = true
            discount = 2
        }
        else {
            fixDiscountLabel.text = homeEvent.discount.suffix(2) + "%"
            variableDiscountLabel.isHidden = true
        }
        if homeEvent.bannerText == "" {
            bannerView1.isHidden = true
            bannerView2.isHidden = true
            bannerView3.isHidden = true
            bannerView4.isHidden = true
        }
        else {
            if homeEvent.bannerText == "Angebot endet heute!" {
                banner = 1
            }
            else if homeEvent.bannerText == "Überregionales Top-Angebot" {
                banner = 2
            }
            else if homeEvent.bannerText == "Nur noch wenige Tickets" {
                banner = 3
            }
            else if homeEvent.bannerText == "Angebot endet morgen!" {
                banner = 4
            }
            else {
                bannerView1.isHidden = true
                bannerView2.isHidden = true
                bannerView3.isHidden = true
                bannerView4.isHidden = true
            }
        }
        eventTitleLabel.text = homeEvent.title
        eventSubTitleLabel.text = homeEvent.subtitle
        if homeEvent.themePage == "1" {
            themePage = true
            locationImageView.isHidden = true
            eventDatesLabel.isHidden = true
            eventLocationLabel.isHidden = true
        }
        else {
            eventDatesLabel.text = homeEvent.dates
            eventLocationLabel.text = homeEvent.location
        }
        setupViews()
    }

    override func prepareForReuse() {
        eventImageView.image = nil
        genreLabel.text = nil
        teamEventLabel.isHidden = true
        giftLabel.isHidden = true
        fixDiscountLabel.text = nil
        variableDiscountLabel.text = nil
        eventTitleLabel.text = nil
        eventSubTitleLabel.text = nil
        eventDatesLabel.text = nil
        eventLocationLabel.text = nil
    }

    weak var homeControllerDelegate: HomeControllerDelegate?

    override init(frame: CGRect) {
        super.init(frame: frame)
//        setupViews() //genreLabel just displaying one Letter
    }

    func setupViews() {
        addSubview(genreLabel)
        if discount == 1 {
            addSubview(fixDiscountLabel)
        }
        else {
            addSubview(variableDiscountLabel)
        }

        //setting Subviews for other labels, views ...

        _ = genreLabel.anchor(topAnchor, left: leftAnchor, bottom: nil, right: nil, topConstant: 16, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: genreLabel.intrinsicContentSize.width, heightConstant: 30)

        if discount == 1 {
                _ = fixDiscountLabel.anchor(topAnchor, left: nil, bottom: nil, right: rightAnchor, topConstant: imageHeight - 32, leftConstant: 0, bottomConstant: 0, rightConstant: 8, widthConstant: 64, heightConstant: 64)

                _ = eventTitleLabel.anchor(eventImageView.bottomAnchor, left: leftAnchor, bottom: nil, right: fixDiscountLabel.leftAnchor, topConstant: 6, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: (UIScreen.main.bounds.width - 60 - imageHeight) / 4 - 6)
            }
            else {
                _ = variableDiscountLabel.anchor(topAnchor, left: nil, bottom: nil, right: rightAnchor, topConstant: imageHeight - 32, leftConstant: 0, bottomConstant: 0, rightConstant: 8, widthConstant: 64, heightConstant: 64)

                _ = eventTitleLabel.anchor(eventImageView.bottomAnchor, left: leftAnchor, bottom: nil, right: variableDiscountLabel.leftAnchor, topConstant: 6, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: (UIScreen.main.bounds.width - 60 - imageHeight) / 4 - 6)
            }

        //setting the constraints for other labels, views ...

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

I want the genreLable to have the width to fit the text and not to change after scrolling. Also the discountLabel should not disappear after scrolling.

Answer 1

Try to add the labels into the contentView of the CollectionViewCell, not the view itself.

Instead of:

addSubview(label)

do

contentView.addSubview(label)