ios - 从 url 获取文本的 Swift 标签在滚动 collectionView 时会改变大小

Question

设置:
在CollectionView 中有多个单元格。它们都有一个 genreLabel(所有单元格的文本都不同)和一个 discountLabel。

我期望发生的事情:
每个genreLabel足够宽以显示相应的文本，并且滚动后不会改变其大小。此外，discountLabel 在滚动后不应消失。

实际发生的情况:对于第一个单元格，文本按照我的预期显示，但是当我在 CollectionView 中向下滚动时，一些 genreLabel 变得比文本宽，所以文本不再完全显示。函数setupViews()用于在CollectionViewCell中创建约束，并在函数configure()中设置属性。此外还有第二个问题:当 genreLabel 变小时，discountLabel 也会消失。

我已经尝试过的:
我尝试将 setupViews() 的调用放在不同的地方。当我将其放入 CollectionViewCell 的 init() 时，genreLabel 非常小，它只显示文本的一个字母。当我将它放在 configure() 的末尾或 collectionView(cellForItemAt) 中的 cell.configure() 之后时，我遇到了问题现在。

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)
        }
    }
}

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")
    }
}

Answer 1

尝试将标签添加到 CollectionViewCell 的 contentView 中，而不是 View 本身。

而不是:

addSubview(label)

做

contentView.addSubview(label)