Swift UIPickerView 最后一列数据导致致命崩溃

Posted 2023-02-24

【中文标题】Swift UIPickerView 最后一列数据导致致命崩溃

【英文标题】：Swift UIPickerView last column of data causes fatal crash

【发布时间】：2018-04-09 17:12:29

【问题描述】：

这很奇怪，因为我有两列数据，其中第一列指示第二列在选择时将显示的内容。一旦我到达第一列中的最后一个字符串，它就会抛出一个致命错误，否则它会正常工作。当我到达“运输”时，会抛出错误。在“numberOfRowsInComponent”-“return secondColumnData[selected].count”上抛出错误。

var categories = ["Attractions & Entertainment", "Eating & Drinking", "Financial Institution", "Lodging Establishment", "Medical & Health", "Public Services & Buildings", "Service", "Stores & Shopping", "Transportation"]

var transportation = ["Car Rental Agency", "Driving School", "Gas Station", "Parking Garage", "Parking Lot", "Taxi Service", "Transportation Service", "Truck Rental Agency"]

var secondColumnData: [[String]] = []


override func viewDidLoad() 
    super.viewDidLoad()

    pickerView.delegate = self
    pickerView.dataSource = self
    pickerView.setValue(UIColor.white, forKey: "textColor")

    secondColumnData = [attrationsAndEntertainment, eatingAndDrinking, financialInstitution, lodgingEstablishment, medicalAndHealth, service, storesAndShopping, transportation]




 override func viewDidAppear(_ animated: Bool) 
    super.viewDidAppear(animated)
    picker.delegate = self



func numberOfComponents(in pickerView: UIPickerView) -> Int 
    return 2


func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int 
    if component == 0 
        return categories.count
     else 
        let selected = pickerView.selectedRow(inComponent: 0)

        return secondColumnData[selected].count
    

【问题讨论】：

secondColumnData[selected] 不是越界了吗？

不确定你的意思，错误是“线程1：致命错误：索引超出范围”

我的编译器返回正确数量的字符串...

【参考方案1】：

这是因为secondColumnData 数组包含 8 个元素，而不是 categories 中的 9 个元素

【讨论】：

该死，我很愚蠢。我看了两次这些数组，没有看到，哈哈，谢谢。很抱歉浪费了你们的时间