Swift 数组不返回所有值

Posted 2023-03-03

【中文标题】Swift 数组不返回所有值

【英文标题】：Swift Array Not Returning All Values

【发布时间】：2018-03-08 04:59:19

【问题描述】：

我正在为 ios 创建一个简单的投票应用程序。我创建了一个 tableviewcontroller，我想从数组中加载类别名称。

我的问题是数组只返回集合中的最后一个值（“林肯先生”）。

我要做的是将每个类别名称显示在一个单元格中，以便用户可以选择它，并且根据单击的单元格在下一个视图控制器上显示选项。

显示for in循环以返回单元格的代码部分是

for categoryText in list 
    cell.textLabel?.text = categoryText.categoryName

---

//
//  CatagoryTableViewController.swift
//  xlsxreaderwriter
//
//  Created by Ahmeeya Goldman on 2/11/18.
//  Copyright © 2018 Ahmeeya Goldman. All rights reserved.
//

import UIKit

class CatagoryTableViewController: UITableViewController 

    var list = [Categories]()

    var myIndex = 0

    override func viewDidLoad() 
        super.viewDidLoad()

        list.append(Categories(categoryText: "In The Mix", choiceA: "Ivy Smith", choiceB: "Shay West", choiceC: "Donald Allen", choiceD: "Zay (Wooo)"))
        list.append(Categories(categoryText: "Best Male Organization",choiceA: "People Standing United", choiceB: "Young Kings Movement", choiceC: "Gentlemen Qualities", choiceD: "" ))
        list.append(Categories(categoryText: "Best Female Organization", choiceA: "RSVP", choiceB: "STARS", choiceC: "NCNW", choiceD: "BSLS"))
        list.append(Categories(categoryText: "Best Dancer", choiceA: "Ansord Rashied", choiceB: "Donald Allen", choiceC: "Isis Ferguson", choiceD: "Jada Mosoey"))
        list.append(Categories(categoryText: "Most Likely To Brighten Your Day", choiceA: "Bar'rae Choice", choiceB: "Tytiana Jackson", choiceC: "Ivery Tanner", choiceD: "Chinonye Agu"))
        list.append(Categories(categoryText: "Best Modeling Troop", choiceA: "Ziana Fashion Club", choiceB: "We R 1 Family", choiceC: "", choiceD: ""))
        list.append(Categories(categoryText: "Best Male Friend Group", choiceA: "Quincy, Kraig, and Kiefer", choiceB: "WOOO", choiceC: "Kevin, Ivery, Kendell, and Marc", choiceD: "Dre, Eli, Jafari, and Ryan"))
        list.append(Categories(categoryText: "Best Female Friend Group", choiceA: "Omolara, Xela, Reggie, and Shania", choiceB: "Dior, Ashleigh, Tanya, Asha, Jazamine, and Aliea", choiceC: "Damo, Dani, Ty,Tati, and Ivy", choiceD: "Ahmani, Leshay, and Nyia"))
        list.append(Categories(categoryText: "Best Dressed Male", choiceA: "Dane Tyree", choiceB: "Ajamu Davis", choiceC: "Taj Green", choiceD: "Isiah Thomas"))
        list.append(Categories(categoryText: "Best Dressed Female", choiceA: "Imani Stamford", choiceB: "Ivy Smith", choiceC: "Tyler Murray", choiceD: "Kam"))
        list.append(Categories(categoryText: "Best DJ", choiceA: "Dj Topchoice", choiceB: "Dj Mizzy", choiceC: "Dj Che", choiceD: ""))
        list.append(Categories(categoryText: "Best Clothing Line", choiceA: "Visonary Society", choiceB: "Rare World", choiceC: "Handwritten", choiceD: "Soigne Y Pree"))
        list.append(Categories(categoryText: "Best Clothing Line", choiceA: "2016", choiceB: "2015", choiceC: "2014", choiceD: "2013"))
        list.append(Categories(categoryText: "Best Miss Lincoln", choiceA: "2016", choiceB: "2015", choiceC: "2014", choiceD: "2013"))
        list.append(Categories(categoryText: "Best Mr Lincoln", choiceA: "2016", choiceB: "2015", choiceC: "2014", choiceD: "2013"))
    

    override func numberOfSections(in tableView: UITableView) -> Int 
        return 1
    

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
        let count = list.count
        return count
    

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
        let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath)

       **for categoryText in list 
        cell.textLabel?.text = categoryText.categoryName
        **
        print(cell)
        return cell
    

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 
        myIndex = indexPath.row
        performSegue(withIdentifier: "showNominees", sender: self)
    

【问题讨论】：

list.count 返回什么？

它返回 15 个单元格，因为该数组有 15 个类别。 list 中的 for categoryText 代码使所有单元格标题等于数组中的最后一项。

【参考方案1】：

您不应该在cellForRowAt 中使用循环。获取特定于给定indexPath 的值：

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
    let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath)

    let category = list[indexPath.row]
    cell.textLabel?.text = category.categoryName

    return cell

【参考方案2】：

您不必遍历 cellForRowAt 中的每个元素，而是这样做：

cell.textLabel?.text = list[indexPath.row].categoryName

【讨论】：

感谢您的帮助

【参考方案3】：

您需要使用 indexPath 在索引处获取价值：

但是在category.categoryName 或你的结构中categoryName 的值没有定义。 我认为您将默认值分配给变量categoryName，即categoryName = Mr.Lincoln

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
    let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath)

    let category = list[indexPath.row]
    cell.textLabel?.text = category.categoryName

    return cell

【讨论】：

这个答案与@rmaddy 的有什么不同！

@triandicAnt 看看大胆的建议。

@triandicAnt 所有答案都在一两分钟内发布。没关系。