ios - Pickerview 内容未显示

Question

我正在尝试获取其中包含数字列表的选择器 View 。

到目前为止，我可以获得包含所有数字的字符串，但是当将其放入选择器 View 时，选择器 View 始终为空。你能看看我的代码，让我知道哪里出错了吗？

import Foundation
import UIKit

class PickerView: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {
    @IBOutlet weak var questionNumberPickers: UIPickerView!

    var Category: String!
    var numbDict: String!
    var QuestionNumber: String!
    var cell: UITableViewCell?
    var currentTopicIndex = Int()
    var setCount = Int()
    var setNumber = Int()
    var pickerString2 = [String]()
    var selectedQuestionNumber: String!
    var contacts: NSArray?
    var dictContacts = Int()
    var pickerArray: NSArray?

    @IBOutlet weak var numberOfRow: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        print(currentTopicIndex)

        questionNumberPickers.delegate = self
        questionNumberPickers.dataSource = self

        self.numberOfRow.text = "0"
        setCount = Quiz.quizzes[currentTopicIndex].plist.count

        let min = 1
        let max = setCount
        let intArray: [Int] = Array(min...max)
        print(intArray)

        let pickerString2 = intArray.map
        {
            String($0)
        }

        self.questionNumberPickers?.reloadAllComponents()

        print(pickerString2)
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if(segue.identifier == "questionToQuiz"){

            //   Get the new view controller using [segue destinationViewController].
            let detailScene = segue.destination as! QuizController


            detailScene.numberOfQuestions = numberOfRow.text as String!
        }
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return pickerString2.count
    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return pickerString2[row]
    }

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        numberOfRow.text  = pickerString2[row]
    }
}

Answer 1

从 let pickerString2 = intArray.map 中删除“let” { 字符串($0)

在 viewDidLoad 中，您正在初始化名为 pickerString2 的第二个变量。

let pickerString2 = intArray.map
    {
        String($0)
    }

应该是这样的

pickerString2 = intArray.map
    {
        String($0)
    }

但是您正在尝试用另一个空的 pickerString2 变量填充 pickerview。

var pickerString2 = [String]()