ios - 标签从 CollectionViewCell 中消失

Question

我使用的是 collectionView，在第一个 indexPath 行中，我有从 Firebase 检索到的第一个 viewController 的数据摘要，从第二个开始，我隐藏了所有标签并显示了其他标签，但是当我返回到第一个 View 并返回时进入collectionView标签消失

是约束问题还是我的代码不好？可以看到右边3个标签消失了

之前:

之后:

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cella = collectionView.dequeueReusableCell(
            withReuseIdentifier: "cella", for: indexPath) as! ChatViewCell
        cella.LabelEur.text = ""
        if (indexPath.row == 0){
            collectionView.selectItem(at: indexPath, animated: true, scrollPosition: UICollectionViewScrollPosition.centeredHorizontally)
            cella.layer.backgroundColor = UIColor("#FFA000").cgColor

            cella.Label1.textColor = .white
            cella.LabelR.textColor = .white
            cella.Date.textColor = .white
            cella.Time.textColor = .white
            cella.City.textColor = .white

            let user = Chat[indexPath.row]
            cella.Label1.text = user.sender
            cella.LabelEur.isHidden = true
            cella.euro.isHidden = true
            cella.Tipo.isHidden = false
            cella.Quantita.isHidden = false
            cella.Misure.isHidden = false
            cella.TIpo2.isHidden = false
            cella.Label1.isHidden = false
            cella.labeldata.isHidden = true
            cella.labelora.isHidden = true
            cella.Date.text = user.date
            cella.Time.text = user.time

            if user.caricoc == "1" {
                cella.CaricoC.isHidden = false
            } else { cella.CaricoC.isHidden = true }
            if user.runflat == "1" {
                cella.RunFlat.isHidden = false
            } else { cella.RunFlat.isHidden = true }
            if user.rinforzato == "1" {
                cella.Rinforzato.isHidden = false
            } else { cella.Rinforzato.isHidden = true }
            cella.montaggio.isHidden = true
            cella.oraMontaggio.isHidden = true
            cella.Distanza.isHidden = true
            cella.categoria.isHidden = false
            cella.categoria.text = user.cat
            cella.TIpo2.text = user.tipo
            cella.Misure.text = user.model
            cella.Tipo.text = user.marca
            cella.Quantita.text = user.numero
            cella.LabelR.text = "Ha inserito una richiesta"
            //key2 = user.key
            misure1 = user.model
            caricC = user.caricoc
            rnf = user.runflat
            rinf = user.rinforzato
            tipo = user.tipo
            marca = user.marca
            quantita = user.numero
            cat = user.cat
            //last = user.lastname
            lat = user.lat
            lng = user.lng
        }else{

        }
        if (indexPath.row >= 1){
            let user = Chat[indexPath.row]
            cella.Label1.text = ""
            cella.Date.text = user.date
            cella.Time.text = user.time
            cella.RunFlat.isHidden = true
            cella.Rinforzato.isHidden = true
            cella.CaricoC.isHidden = true
            cella.LabelEur.isHidden = false
            cella.categoria.isHidden = true
            cella.euro.isHidden = false
            cella.TIpo2.isHidden = true
            cella.Tipo.isHidden = true
            cella.Quantita.isHidden = true
            cella.labelora.isHidden = false
            cella.labeldata.isHidden = false
            cella.montaggio.isHidden = false
            cella.oraMontaggio.isHidden = false
            cella.Distanza.isHidden = false
            cella.oraMontaggio.text = user.oraApp
            cella.montaggio.text = user.dataApp
            cella.Misure.isHidden = true

            let prezzo: Float = (Float(user.text)?.multiplied(by: 1.10))!
            let nenno: Float = 3.234
            let prezzo2 = String(describing: NSDecimalNumber(string: String(format:"%.0f", prezzo)))
            cella.LabelEur.text = prezzo2
            cella.LabelR.isHidden = true
            cella.layer.backgroundColor = UIColor("#FFFFFF").cgColor
            let posInt = Int(user.positiondef)
            if (posInt! <= 5) {
                cella.Distanza.text = "A meno di 5km"
            } else if (posInt! <= 10) {
                cella.Distanza.text = "A meno di 10km"
            } else if (posInt! <= 15) {
                cella.Distanza.text = "A meno di 15 km"
            }
            /*
             if (user.positiondef != nil) {
             if (user.positiondef.hasPrefix("0")) {
             cella.Distanza.text = "Nelle vicinanze"
             } else {
             cella.Distanza.text = user.positiondef+"KM"
             }
             }*/
            cella.City?.text = user.city
            self.Chat = self.Chat.sorted{ $0.text.compare($1.text, options: .numeric) == ComparisonResult.orderedAscending }

        }

        return cella

    }

Answer 1

我相信约束是正确的。它们不应该在 viewController 转换之间改变。问题可能出在标签的“textColor”属性上。在第一个单元格中，您将颜色设置为白色。在第二个中，它们应该是黑色的。我相信它们的显示不仅仅是因为它们与背景颜色相同。尝试在第二个“if”语句中将标签的 textColor 设置为黑色。

if indexPath.row >= 1 {
    //set textColor of labels here.
}

Collection Views 使用可重复使用的单元格，因此标签的 textColor 可能仍然是白色的，因为之前使用过。