UIPickerView 重新加载不起作用

Question

我有一个选择器视图，其中包含两个组件，每个组件有五行。

在第一个组件中，我有五个汽车品牌：Toyota、Ford、Honda 等...在第二个组件中，我有五个相关品牌的模型。

当您更改品牌时，模型应随之更新。

我遇到的问题是我似乎无法让组件 2 根据 1 进行更新。

以下是代码的快照以及我目前在 sim 上的内容。

var keyArray: [String] = ["Nissan","Honda","Toyota","Ferrari","Bentley"]
var makeIndex = 0
var carDict : [String :[String]] = ["Nissan" : ["Sentra","Xterra","Versa","Altima","Maxima"], "Honda": ["Accord","Civic","Odyssey","Civic SE", "Accord LE"],"Toyota":["Corolla","Camry","4 Runner","Corolla LE","Camry SE"],"Ferrari": ["La Ferrari", "Modena", "Testarrosa","360 Spyder", "California"], "Bentley": ["Arnage","Continental","Flying Spur","Continental GT"]]

func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return 5
}

func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 2

}
@IBOutlet weak var pickerLabel: UILabel!
@IBOutlet weak var speedLabel: UILabel!
override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
    speedLabel.text = String(vehicleInst.speed)
}

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {

    switch component {

    case 0:

        if component == 0 {

            pickerView.reloadComponent(1)
            return keyArray[row]
        }
        return keyArray[row];



    case 1:


        var modelarray = carDict[keyArray[makeIndex]]

return modelarray![row];

    default:

        return "nothing";
    }



}

Answer 1

当用户从组件 0 选择品牌时，您需要更新组件 1。实施 pickerView:didSelectRow:inComponent:，然后在那里更新您的 makeIndex：

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if component == 0 {
        makeIndex = row
        pickerView.reloadComponent(1)
    }
}

这里是对pickerView:titleForRow:forComponent:

的相应修改

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {

    switch component {

    case 0:

        return keyArray[row]

    case 1:

        var modelarray = carDict[keyArray[makeIndex]]

        return modelarray![row]

    default:

        return "nothing"
    }
}

顺便说一句，你只有 4 辆 Bentley 车型，因为你声称有 5 辆，所以导致崩溃。

UIPickerView 重新加载不起作用

UIPickerView reloading not working

uipickerview

ios

swift