ios - UIPickerView.selectRow 滚动导致崩溃

Question

我有3个UIPickerView，每个都有不同的值:

let pickerContext = ["Aucun","@office","@computer","@home","@meeting","@read","@achat","@call"]
let pickerStatus = ["LATE","IN-PROCESS","COMPLETED","NOT-STARTED"]
let pickerField = ["INBOX","TODO","WAITING","MAYBE","NOTE"]

func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    if(pickerView.isEqual(ContextPickerView)){
        return pickerContext.count
    }
    if(pickerView.isEqual(StatusPickerView)){
        return pickerStatus.count
    }
    if(pickerView.isEqual(FieldPickerView)){
        return pickerField.count
    }
    return 0
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
    if(pickerView.isEqual(ContextPickerView)){
        if contextText != ""{
            println(contextText)
            for (index, context) in enumerate(pickerContext)
            {
                if context == contextText
                {
                    ContextPickerView.selectRow(index, inComponent: 0, animated: false)
                }
            }
        }
        return pickerContext[row]
    }
    if(pickerView.isEqual(StatusPickerView)){
        if statusText != ""{
            println(statusText)
            for (index, status) in enumerate(pickerStatus)
            {
                if status == statusText
                {
                    StatusPickerView.selectRow(index, inComponent: 0, animated: false)
                }
            }
        }
        return pickerStatus[row]
    }
    if(pickerView.isEqual(FieldPickerView)){
        if fieldText != ""{
            println(fieldText)
            for (index, field) in enumerate(pickerField)
            {
                if field == fieldText
                {
                    FieldPickerView.selectRow(index, inComponent: 0, animated: false)
                }
            }
        }
        return pickerField[row]

    }

    return ""
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if(pickerView.isEqual(ContextPickerView)){
        contextText = pickerContext[row]
    }
    if(pickerView.isEqual(StatusPickerView)){
        statusText = pickerStatus[row]
    }
    if(pickerView.isEqual(FieldPickerView)){
        fieldText = pickerField[row]
    }

}

UIPickerViews 填充得很好，具体取决于从一个 ViewController 到带有 PickerViews 的 View Controller 传递的值，pickerViews 的光标位于正确的位置，一切都很好，但是..当我尝试交换任何 PickerView 的光标，应用程序都会在相关 *****PickerView.selectRow(index, inComponent: 0,animated: false) 上崩溃。一旦页面收费，我就无法更改任何光标。

我认为这是因为如果 if context == contextText 事实上，如果我设置 contextText、statusText 或 fieldText 为“”，光标设置为第一个值，但我可以根据需要更改它们。

有什么想法、技巧可以避免这些崩溃吗？

谢谢

Answer 1

不尝试在 pickerview:titleForRow... 方法中使用 PickerView.selectRow 怎么样？当选择器 View 使行准备好显示时，将调用该方法。

在使用数据源设置选择器 View 后，只需循环数据并找到 contentText/statusText/fieldText 的索引，然后(如果找到)调用 ContextPickerView/StatusPickerView/FieldPickerView.selectRow。