Question

请原谅我的无知。我正在从头开始学习。

我试图根据视图顶部的pickerView的选择填充多个pickerView实例。我希望其余pickerview中显示的选择取决于在第一个pickerview中选择的项目。

我总共有6个pickerViews。第一个进行一般选择，我想将其余部分作为基础。

Pickerview1具有4个组件。如果用户选择组件4，则所有剩余的pickerViews都会显示选择。如果用户选择组件2或3，我希望pickerView 4和5显示N / A，而其他显示选择。如果用户选择组件1，我希望pickerViews 3-5显示N / A，而1-2显示选项。

我假设要执行此操作，我将需要pickerView1中所选组件的索引值来为func pickerView做出if else语句（_ pickerView：UIPickerView，numberOfRowsInComponent等。

我在文档中找到了selectedRow（inComponent :)，但是找不到在我的情况下如何实现它的有效示例。

到目前为止，我的代码附带了一些代码片段：导入UIKit

FirstViewController类：UIViewController，UIPickerViewDelegate， UIPickerViewDataSource { func numberOfComponents（在pickerView中：UIPickerView）-> Int { 返回1 }

    var capacities = ["6","9","12","15","18","24"]
    var notUsed = "N/A"
    var oduList = ["MXZ-2C20", "MXZ-3C24", "MXZ-3C30", "MXZ-5C42"]
    var result:Float = 0.0
    var one4num:Float = 1.0
    var factor:Float = 1.08
    var per5ft:Float = 5
    var factory:Float = 98

    var selectedRow = 1

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        selectedRow = pickerView.selectedRow(inComponent: index)
        if pickerView == oduPicker {
            return oduList.count
        }
        else if pickerView == idu1PickerView {
            return capacities.count
        }
        else if pickerView == idu2PickerView {
            return capacities.count
        }
        else if pickerView == idu3PickerView {
            return capacities.count
        }
        else if pickerView == idu4PickerView {
            return capacities.count
        }
        else {
            return capacities.count
        }
    }
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        if pickerView == oduPicker {
            return oduList[row]
        }
        else if pickerView == idu1PickerView {
            return capacities[row]
        }
        else if pickerView == idu2PickerView {
            return capacities[row]
        }
        else {
            return capacities[row]
        }
    }
    @IBOutlet weak var oduPicker: UIPickerView!

    @IBOutlet weak var idu1PickerView: UIPickerView!
    @IBOutlet weak var idu2PickerView: UIPickerView!
    @IBOutlet weak var idu3PickerView: UIPickerView!
    @IBOutlet weak var idu4PickerView: UIPickerView!
    @IBOutlet weak var idu5PickerView: UIPickerView!

    @IBOutlet weak var one4Label: UILabel!
    @IBOutlet weak var one4Slider: UISlider!



    @IBOutlet weak var output: UILabel!




    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.oduPicker.delegate = self
        self.oduPicker.dataSource = self
        self.idu1PickerView.delegate = self
        self.idu1PickerView.dataSource = self
        self.idu2PickerView.delegate = self
        self.idu2PickerView.dataSource = self
        self.idu3PickerView.delegate = self
        self.idu3PickerView.dataSource = self
    }

    @IBAction func one4Slider(_ sender: Any) {
        one4Label.text = "\(one4Slider.value)"
    }
    @IBAction func three8Slider(_ sender: Any) {
        three8Label.text = "\(three8Slider.value)"


    }
    @IBAction func calculateButton(_ sender: Any) {
        result = factor*(one4num-factory)/per5ft
        output.text = "\(result)"
    }
}

如果我以这种方式实施建议：

import UIKit

class FirstViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 1
}

var capacities = ["6","9","12","15","18","24"]
var notUsed = ["N/A"]
var oduList = ["MXZ-2C20", "MXZ-3C24", "MXZ-3C30", "MXZ-5C42"]
var result:Float = 0.0
var one4num:Float = 1.0
var factor:Float = 1.08
var per5ft:Float = 5
var factory:Float = 98

var rowSelected: Int?


func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if pickerView == oduPicker{
        self.rowSelected = row
        // make anything
    }

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {

    if pickerView == oduPicker {
        return oduList.count
    }
    else if pickerView == idu1PickerView {
        return capacities.count
    }
    else if pickerView == idu2PickerView {

        return capacities.count
    }
    else if pickerView == idu3PickerView {
        if rowSelected!  < 2 {
            return 1
        }
        else {
            return capacities.count
        }
    }
    else if pickerView == idu4PickerView {
        if rowSelected! < 3 {
            return 1
        }
        else {
            return capacities.count
        }
    }
    else {
        if rowSelected! < 4 {
            return 1
        }
        else {
            return capacities.count
        }
    }
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    if pickerView == oduPicker {
        return oduList[row]
    }
    else if pickerView == idu1PickerView {
        return capacities[row]
    }
    else if pickerView == idu2PickerView {
        return capacities[row]
    }
    else if pickerView == idu3PickerView {
        if rowSelected! < 2 {
            return notUsed[row]
        }
        else {
            return capacities[row]
        }
    }
    else if pickerView == idu4PickerView {
        if rowSelected! < 3 {
            return notUsed[row]
        }
        else {
            return capacities[row]
        }
    }
    else if pickerView == idu5PickerView {
        if rowSelected! < 4 {
            return notUsed[row]
        }
        else {
            return capacities[row]
        }
    }
    else {
        return capacities[row]
    }
}



@IBOutlet weak var oduPicker: UIPickerView!

@IBOutlet weak var idu1PickerView: UIPickerView!
@IBOutlet weak var idu2PickerView: UIPickerView!
@IBOutlet weak var idu3PickerView: UIPickerView!
@IBOutlet weak var idu4PickerView: UIPickerView!
@IBOutlet weak var idu5PickerView: UIPickerView!

@IBOutlet weak var one4Label: UILabel!
@IBOutlet weak var one4Slider: UISlider!



@IBOutlet weak var output: UILabel!




override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    self.oduPicker.delegate = self
    self.oduPicker.dataSource = self
    self.idu1PickerView.delegate = self
    self.idu1PickerView.dataSource = self
    self.idu2PickerView.delegate = self
    self.idu2PickerView.dataSource = self
    self.idu3PickerView.delegate = self
    self.idu3PickerView.dataSource = self
    self.idu4PickerView.delegate = self
    self.idu4PickerView.dataSource = self
    self.idu5PickerView.delegate = self
    self.idu5PickerView.dataSource = self
}

@IBAction func one4Slider(_ sender: Any) {
    one4Label.text = "\(one4Slider.value)"
}

@IBAction func calculateButton(_ sender: Any) {
    result = factor*(one4num-factory)/per5ft
    output.text = "\(result)"
}
}

代码破坏了“ FirstViewController”并似乎使“ numberOfRows”和“ titleForRows”语句以及下面的一系列错误无效。

如果我在这两个功能之后实现：

 else {
        return capacities[row]
    }
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if pickerView == oduPicker{
        self.rowSelected = row
        // make anything
    }



@IBOutlet weak var oduPicker: UIPickerView!

@IBOutlet weak var idu1PickerView: UIPickerView!
@IBOutlet weak var idu2PickerView: UIPickerView!
@IBOutlet weak var idu3PickerView: UIPickerView!
@IBOutlet weak var idu4PickerView: UIPickerView!
@IBOutlet weak var idu5PickerView: UIPickerView!

它破坏了所有的pickerView变量，例如oduPicker等。

如果我尝试将语句带入第一个函数，则如下所示：

var rowSelected: Int?



    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, numberOfRowsInComponent component: Int) -> Int {

    if pickerView == oduPicker {
        self.rowSelected = row
        return oduList.count
    }
    else if pickerView == idu1PickerView {
        return capacities.count
    }...

它再次中断“ FirstViewController”，并显示错误“类型'FirstViewController'不符合协议'UIPickerViewDataSource'”

我也被迫加上“！”在“ rowSelected”之后进行包装/展开。我不确定这是什么意思还是目前重要。

更新：

如果我按照塞缪尔的建议实施这样的话：

import UIKit

FirstViewController类：UIViewController，UIPickerViewDelegate，UIPickerViewDataSource { func numberOfComponents（在pickerView中：UIPickerView）-> Int { 返回1 }

var capacities = ["6","9","12","15","18","24"]
var notUsed = ["N/A"]
var oduList = ["MXZ-2C20", "MXZ-3C24", "MXZ-3C30", "MXZ-5C42"]
var result:Float = 0.0
var one4num:Float = 1.0
var factor:Float = 1.08
var per5ft:Float = 5
var factory:Float = 98

var selectedRow = 1



func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    selectedRow = pickerView.selectedRow(inComponent: index)
    if pickerView == oduPicker {
        return oduList.count
    }
    else if pickerView == idu1PickerView {
        return capacities.count
    }
    else if pickerView == idu2PickerView {

        return capacities.count
    }
    else if pickerView == idu3PickerView {
        if selectedRow  < 2 {
            return 1
        }
        else {
            return capacities.count
        }
    }
    else if pickerView == idu4PickerView {
        if selectedRow < 3 {
            return 1
        }
        else {
            return capacities.count
        }
    }
    else {
        if selectedRow < 4 {
            return 1
        }
        else {
            return capacities.count
        }
    }
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    if pickerView == oduPicker {
        return oduList[row]
    }
    else if pickerView == idu1PickerView {
        return capacities[row]
    }
    else if pickerView == idu2PickerView {
        return capacities[row]
    }
    else if pickerView == idu3PickerView {
        if selectedRow < 2 {
            return notUsed[row]
        }
        else {
            return capacities[row]
        }
    }
    else if pickerView == idu4PickerView {
        if selectedRow < 3 {
            return notUsed[row]
        }
        else {
            return capacities[row]
        }
    }
    else if pickerView == idu5PickerView {
        if selectedRow < 4 {
            return notUsed[row]
        }
        else {
            return capacities[row]
        }
    }
    else {
        return capacities[row]
    }
}




@IBOutlet weak var oduPicker: UIPickerView!

@IBOutlet weak var idu1PickerView: UIPickerView!
@IBOutlet weak var idu2PickerView: UIPickerView!
@IBOutlet weak var idu3PickerView: UIPickerView!
@IBOutlet weak var idu4PickerView: UIPickerView!
@IBOutlet weak var idu5PickerView: UIPickerView!

@IBOutlet weak var one4Label: UILabel!
@IBOutlet weak var one4Slider: UISlider!



@IBOutlet weak var output: UILabel!




override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    self.oduPicker.delegate = self
    self.oduPicker.dataSource = self
    self.idu1PickerView.delegate = self
    self.idu1PickerView.dataSource = self
    self.idu2PickerView.delegate = self
    self.idu2PickerView.dataSource = self
    self.idu3PickerView.delegate = self
    self.idu3PickerView.dataSource = self
    self.idu4PickerView.delegate = self
    self.idu4PickerView.dataSource = self
    self.idu5PickerView.delegate = self
    self.idu5PickerView.dataSource = self
}

@IBAction func one4Slider(_ sender: Any) {
    one4Label.text = "\(one4Slider.value)"
}

@IBAction func calculateButton(_ sender: Any) {
    result = factor*(one4num-factory)/per5ft
    output.text = "\(result)"
}

}

行后出现错误：

selectedRow = pickerView.selectedRow(inComponent: index)

“无法将类型'（Any）-> Int'的值转换为预期的参数类型'Int'”

Answer 1

您可以使用委托的方法。以下方法可以为您提供帮助。 row参数特定于用户选择的行。您可以尝试：

var rowSelected : Int?

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if pickerView == idu1PickerView {
       self.rowSelected = row
       // make anything
    }
    ...
}

如果只有一个组件，则可以使用您编写的方法：

var selectedRow = pickerView.selectedRow(inComponent: 0)

获取在UIPickerView Xcode Swift中选择的组件的索引

1 个答案: