我无法在我的UIPickerView中重新加载基于第一个组件的第二个组件。我试过使用reloadAllComponents,但它要么不起作用,要么崩溃。我要做的是把汽车的牌子放在左边,把汽车的型号放在右边。所以当汽车做出改变时,它会同时改变正确的部件型号。

class RegistrationPage: UIViewController,UIPickerViewDataSource, UIPickerViewDelegate {
    @IBOutlet weak var usernameTextField: UITextField!
    @IBOutlet weak var passwordTextField: UITextField!
    @IBOutlet weak var passwordReTypeTextField: UITextField!
    @IBOutlet weak var makePicker: UIPickerView!
    @IBOutlet weak var modelPicker: UIPickerView!
    @IBOutlet weak var licenseTagTextField: UITextField!
    var picker1Options = []
    var picker2Options = []

    @IBAction func SubmitButton(sender: AnyObject) {

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        makePicker = UIPickerView()
        modelPicker = UIPickerView()
        let makeAndModel = CarMakeModel();

        picker1Options = makeAndModel.makeValues()
        let firstValue = picker1Options.objectAtIndex(0)
        picker2Options = makeAndModel.modelValues(firstValue as! String)

    }

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

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

    }

    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
        if component == 0 {
            return "\(picker1Options[row])"
        } else {
            let makeAndModel = CarMakeModel();
            let currentValue = picker1Options.objectAtIndex(row)
            var picker2ptions = makeAndModel.modelValues(currentValue as! String)
            return "\(picker2ptions[row])"
        }
    }
    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        let makeAndModel = CarMakeModel();
        let currentValue = picker1Options.objectAtIndex(row)
        var picker2ptions = makeAndModel.modelValues(currentValue as! String)
        pickerView.reloadAllComponents()

    }
}


谢谢!

最佳答案

这是一个有效的版本。我创建了自己的CarMakeModel类来测试它。你过度思考了titleForRow功能,这是你的主要问题。另外,在didSelectRow中,需要更新类属性picker2Options而不是局部变量。我改变了其他事情。我建议你逐行比较我的版本和你的版本,看看有什么不同。
另外,只需要一个pickerView,它应该连接到脚本中的一个。你不应该实例化你自己的pickerViews。

class CarMakeModel {
    func makeValues() -> [String] {
        return ["Toyota", "Honda"]
    }

    func modelValues(make: String) -> [String] {
        if make == "Toyota" {
            return ["Camry", "Sienna", "Highlander"]
        } else {
            return ["Accord", "Civic", "Pilot"]
        }
    }
}

class RegistrationPage: UIViewController,UIPickerViewDataSource, UIPickerViewDelegate {
    @IBOutlet weak var usernameTextField: UITextField!
    @IBOutlet weak var passwordTextField: UITextField!
    @IBOutlet weak var passwordReTypeTextField: UITextField!
    @IBOutlet weak var makePicker: UIPickerView!
    @IBOutlet weak var modelPicker: UIPickerView!
    @IBOutlet weak var licenseTagTextField: UITextField!
    var picker1Options:[String] = []
    var picker2Options:[String] = []

    @IBAction func SubmitButton(sender: AnyObject) {

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        //makePicker = UIPickerView()
        //modelPicker = UIPickerView()
        let makeAndModel = CarMakeModel();

        picker1Options = makeAndModel.makeValues()
        let firstValue = picker1Options[0]
        picker2Options = makeAndModel.modelValues(firstValue)

    }

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

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

    }

    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
        if component == 0 {
            return "\(picker1Options[row])"
        } else {
            return "\(picker2Options[row])"
        }
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        if component == 0 {
            let makeAndModel = CarMakeModel();
            let currentValue = picker1Options[row]
            picker2Options = makeAndModel.modelValues(currentValue)
            pickerView.reloadAllComponents()
        }
    }
}

关于xcode - 在UI Picker View Swift中重新加载组件,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/30832489/

10-12 14:36
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