swift - 快速uipickerview第二个组件selectrow不起作用

我在斯威夫特有一个带两个组件的pickerview。除了我想用selectrow在第二个组件中设置行之外，它是有效的。当用户重新加载应用程序时，我们已经设置了一个值。第一个组件selectrow可以工作。
这是我的代码：

    override func viewDidLoad() {
    super.viewDidLoad()

    print("In viewDidLoad")

    detailArmy.loadarmy(detailArmy, armymember: detailItem)

    myGeneralPicker.dataSource = self
    myGeneralPicker.delegate = self
    // Set General Picker View to current value
    let general = generalTypeInfo()
    picker1Options = general.generalType()
    print("Detail Item general: \(detailArmy.general)")
    if detailArmy.general == "" {
        myGeneralPicker.selectRow(0, inComponent: 0, animated: false)
        picker2Options = general.generalInfo("None")
    } else {
        myGeneralPicker.selectRow(picker1Options.indexOf(detailArmy.general)!, inComponent: 0, animated: false)
        picker2Options = general.generalInfo(detailArmy.general)
    }
    print("Detail Item general Type: \(detailArmy.generaltype) picker2Options: \(picker2Options)")
    if detailArmy.generaltype == "" {
        myGeneralPicker.selectRow(0, inComponent: 1, animated: false)
    } else {
        //myGeneralPicker.selectRow(picker2Options.indexOf(detailArmy.generaltype)!, inComponent: 1, animated: false)
        myGeneralPicker.selectRow(4, inComponent: 1, animated: false)
    }
}
    //MARK: Delegates and data sources
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    //println("In numberOfComponenetsInPickerView pickerView: \(pickerView)")
    return 2
}

func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    if component == 0 {
        return picker1Options.count
    } else {
        return picker2Options.count
    }
}

//Mark: Delegates
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    //var dicerow = dice[row]
    print("titleForRow row: \(row) component: \(component)")
    if component == 0 {
        return String(picker1Options[row])
    } else {
        return String(picker2Options[row])
    }
}

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if component == 0 {
        generalpickinfo = picker1Options[row]
        print("pickerView general selected: \(generalpickinfo)")
        let general = generalTypeInfo()
        picker2Options = general.generalInfo(picker1Options[row])
        pickerView.reloadAllComponents()
        myGeneralPicker.selectRow(0, inComponent: 1, animated: false)
    } else {
        generalpicktype = picker2Options[row]
        print("pickerView general type selected: \(generalpicktype)")
    }
}

func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView?) -> UIView {
    print("viewForRow row: \(row) component: \(component)")
    let pickGeneralLabel = UILabel()
    pickGeneralLabel.textAlignment = .Center
    if component == 0 {
        pickGeneralLabel.text = String(picker1Options[row])
    } else {
        pickGeneralLabel.text = String(picker2Options[row])
    }
    return pickGeneralLabel
}

class generalTypeInfo {
    func generalType() -> [String] {
        return ["None","C-in-C","Subordinate","Ally"]
    }

    func generalInfo(type: String) -> [String] {
        if type == "None" {
            return ["None"]
        } else {
            return ["None","Brilliant","Inert"]
        }
    }

    func generalTypeIndex(type: String) -> Int {
        let generalTypeDict = ["None": 0, "C-in-C": 1, "Subordinate": 2, "Ally": 3]
        return generalTypeDict[type]!
    }

    func generalInfoIndex(type: String) -> Int {
        let generalInfoDict = ["None": 0, "Brilliant": 1, "Inert": 2]
        return generalInfoDict[type]!
    }
}

在我目前的代码中，我特意在这行中输入了一个值4：

myGeneralPicker.selectRow(4, inComponent: 1, animated: false)

上面这一行有我想运行的正确代码，但是我把它放进去是因为它应该会使应用程序崩溃，因为没有第四个值。它完全忽略了这一点。
有人告诉我这是怎么回事吗？谢谢。

最佳答案

所以，问个问题，然后找出答案。。
答案是将selectrow移到ViewDidAppear中。
我在这里找到了解决办法：
UIPickerView selectRow doesn't works
谢谢