如何解决问题 UIPickerView 致命错误：索引超出范围 [IOS Swift 5.1 Xcode 11.2]

Posted 2023-02-24

【中文标题】如何解决问题 UIPickerView 致命错误：索引超出范围 [IOS Swift 5.1 Xcode 11.2]

【英文标题】：How to Solve problem UIPickerView Fatal error: Index out of range [IOS Swift 5.1 Xcode 11.2]

【发布时间】：2019-12-19 09:05:23

【问题描述】：

我正在尝试获取UIPickerView 的选定值 运行应用程序时。但我得到错误，

致命错误：索引超出范围

我通过print("selected ==>\(selected)") 在numberOfRowsInComponent 函数中进行调试。我通过调试为 0 得到 selected 的值。

如何解决这个问题？

Value From Postman
- Plandate function
http://xxx.xxx.xxx.xx/ProjectService/PODService.svc/GetPlanDate/2
"[      \"PlanDate\": \"26/08/2019\",    \"PlanDateFullFormat\": \"20190826\"  ,      \"PlanDate\": \"27/08/2019\",    \"PlanDateFullFormat\": \"20190827\"  ]"

- PlanShipment
http://xxx.xxx.xxx.xx/ProjectService/PODService.svc/GetShipment/2/20190826
"[      \"Shipment\": \"4505023278\"  ,      \"Shipment\": \"4505023279\"  ]"
http://xxx.xxx.xxx.xx/ProjectService/PODService.svc/GetShipment/2/20190827
"[      \"Shipment\": \"4505023244\"  ,      \"Shipment\": \"4505023274\"  ]"

Return Value From JSON
- Plandate function
http://xxx.xxx.xxx.xx/ProjectService/PODService.svc/GetPlanDate/2
pplandateCategories ==>["20190826", "20190827"]

- PlanShipment
http://xxx.xxx.xxx.xx/ProjectService/PODService.svc/GetShipment/2/20190827
getpShipmentDCPlanData ==>["4505023244", "4505023274"]

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

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int 
        if component == 0 
            return pPlandateCategories.count
        else
            let selected = pickerview.selectedRow(inComponent:0)
           return pShipmentCategories[selected].count ———>. Thread 1: Fatal error: Index out of range
        
    

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? 
        if component == 0 
            return pPlandateCategories[row]
        else
            let selected = pickerview.selectedRow(inComponent:0)
            return pShipmentCategories[selected][row]
        
    

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) 
        if component == 0
            pickerview.reloadComponent(1)

        else
            let selected = pickerview.selectedRow(inComponent:0)
//            getpPlanDatePickerView.text = "PlanDate:" + " " + pplandateCategories[selected][row]
            someTextField.text = "Shipment:" + " " + pShipmentCategories[selected][row]
        
    

Error when Run Project 
My WebService ==> http://xxx.xxx.xxx.xx/ProjectService/PODService.svc/GetPlanDate/2GetPlanDate/2
Fatal error: Index out of range
2019-12-19 10:55:14.459056+0700 pickerDateAndShipment[782:19020] Fatal error: Index out of range

【参考方案1】：

只有在异步加载组件的数据并且在第一次重新加载表视图时数据源为空时才会发生崩溃。

为了避免崩溃检查pShipmentCategories数组是否为空

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int 
    if component == 0 
        return pPlandateCategories.count
     else 
        let selected = pickerview.selectedRow(inComponent:0)
        return pShipmentCategories.isEmpty ? 0 : pShipmentCategories[selected].count
    

【讨论】：

我收到更多错误致命错误：在标题箭头 didSelectRow 函数let selected = pickerview.selectedRow(inComponent:1) return pShipmentCategories.isEmpty ? 0 : pShipmentCategories[selected][row] 中调试后索引超出范围@ -> 如果使用 0 无法将“Int”类型的返回表达式转换为“字符串”类型？和致命错误：索引超出范围

didSelectRow 应该可以在没有任何更改的情况下工作。潘乔的建议是错误的

感谢您的回答，didSelectRow。我写对了吗？ ` func pickerView (_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) if component == 0 pickerview.reloadComponent (1) else let selected = pickerview.selectedRow (inComponent: 1) print ("selected didSelectRow ==> \ (selected)") someTextField.text = "Shipment:" + "" + pShipmentCategories [selected] [row] -> 致命错误：索引超出范围 `

谢谢解答，我的App运行正常没有报错