如何在不弄乱内容的情况下标记 dequeueReusableCell？

Posted 2023-02-27

【中文标题】如何在不弄乱内容的情况下标记 dequeueReusableCell？

【英文标题】：How to tag a dequeueReusableCell without mess the content?

【发布时间】：2017-07-07 03:43:24

【问题描述】：

我在列表中使用了dequeueReusableCell，单元格中有 4 个 UILabel。下面有截图。

无论哪个标签有“-”前缀，都会是红色，但滚动几页后，数字变得一团糟。想知道有没有办法避免这种情况？

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
    let cell = tableView.dequeueReusableCell(withIdentifier: "RecipeTableCell", for: indexPath)
    let currentRecipe = recipes?[indexPath.row]
    let colorRed = UIColor(red: 0xFE/255, green: 0x38/255, blue: 0x24/255, alpha: 1) //FE3824

    (cell.viewWithTag(100) as! UIImageView).image = UIImage(named: currentRecipe?.pic ?? "")
    (cell.viewWithTag(200) as! UILabel).text = currentRecipe?.name

    let hungryLabel = cell.viewWithTag(301) as! UILabel
    hungryLabel.text = currentRecipe?.hungry_value
    if (currentRecipe?.hungry_value!.hasPrefix("-"))! 
        hungryLabel.textColor = colorRed
    

    let healthLabel = (cell.viewWithTag(302) as! UILabel)
    healthLabel.text = currentRecipe?.health_value
    if (currentRecipe?.health_value!.hasPrefix("-"))! 
        healthLabel.textColor = colorRed
    

    let sanityLabel = (cell.viewWithTag(303) as! UILabel)
    sanityLabel.text = currentRecipe?.sanity_value
    if (currentRecipe?.sanity_value!.hasPrefix("-"))! 
        sanityLabel.textColor = colorRed
    

    (cell.viewWithTag(304) as! UILabel).text = currentRecipe?.duration

    return cell

---

谢谢你们。

我在“else”中添加了黑色，它可以工作，谢谢

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
    let cell = tableView.dequeueReusableCell(withIdentifier: "RecipeTableCell", for: indexPath)
    let currentRecipe = recipes?[indexPath.row]
    let colorRed = UIColor(red: 0xFE/255, green: 0x38/255, blue: 0x24/255, alpha: 1)    //FE3824
    let colorBlack = UIColor(red: 74/255, green: 74/255, blue: 74/255, alpha: 1)        //747474

    (cell.viewWithTag(100) as! UIImageView).image = UIImage(named: currentRecipe?.pic ?? "")
    (cell.viewWithTag(200) as! UILabel).text = currentRecipe?.name

    let hungryLabel = cell.viewWithTag(301) as! UILabel
    hungryLabel.text = currentRecipe?.hungry_value
    if (currentRecipe?.hungry_value!.hasPrefix("-"))! 
        hungryLabel.textColor = colorRed
     else 
        hungryLabel.textColor = colorBlack
    

    let healthLabel = (cell.viewWithTag(302) as! UILabel)
    healthLabel.text = currentRecipe?.health_value
    if (currentRecipe?.health_value!.hasPrefix("-"))! 
        healthLabel.textColor = colorRed
     else 
        healthLabel.textColor = colorBlack
    

    let sanityLabel = (cell.viewWithTag(303) as! UILabel)
    sanityLabel.text = currentRecipe?.sanity_value
    if (currentRecipe?.sanity_value!.hasPrefix("-"))! 
        sanityLabel.textColor = colorRed
     else 
        sanityLabel.textColor = colorBlack
    

    (cell.viewWithTag(304) as! UILabel).text = currentRecipe?.duration

    return cell

【问题讨论】：

Edit 你的问题与你的cellForRowAt 方法。

向我们展示您根据前缀“-”管理标签颜色的代码。

细胞被重复使用。在cellForRow 添加一个else 子句，如果值为not 负数，则显式将颜色设置为黑色。

@vadian 谢谢它有帮助

PS：viewWithTag 非常老套。在 IB 中设计一个 custom 单元并使用 outlet。对于灰度颜色，有一个方便的初始化程序let colorBlack = UIColor(white: 74/255, alpha: 1)。

【参考方案1】：

在您的 cellForRowAt 方法中，您需要检查值是否为正，则颜色为黑色，如果为负，则为红色。例如

label.color = black

if negativeValue 
     lagel.color = red