在第三个按钮上使用 UIPickerView 进行依赖选择
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【中文标题】在第三个按钮上使用 UIPickerView 进行依赖选择【英文标题】：Dependent Selection using UIPickerView on 3rd Button 【发布时间】：2020-06-19 22:10:50 【问题描述】：我希望 button3 使用基于 button2 选择的 uipickerview 显示元素。 button3 将依赖于 button2。
[“圆形”：[“X”，“Y”，“Z”]]
[“正方形”：[“X”，“Y”，“Z”]，“椭圆”：[“A”，“B”，“C”]，“矩形”：[“1”，“ 2", "3"]]
[“三角形切割”：[“X”，“Y”，“Z”]，“球体”：[“A”，“B”，“C”]]
这是当前的 xcode 脚本：
import UIKit
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource
@IBOutlet weak var textField_0: UITextField!
@IBOutlet weak var textField_1: UITextField!
@IBOutlet weak var textField_2: UITextField!
@IBOutlet weak var btn1: UIButton!
@IBOutlet weak var btn2: UIButton!
@IBOutlet weak var btn3: UIButton!
@IBOutlet weak var mainPicker: UIPickerView!
private var shapeOptions = ["Option 1", "Option 2", "Option 3"]
private var shape1 = [["Round"],
["Square", "Oval", "Rectangle"],
["Triangle", "Sphere"]]
private var shape2 = [["X", "Y", "Z"],
["A", "B", "C"],
["1", "2", "3"]]
private var _currentSelection: Int = 0
var currentSelection: Int
get
return _currentSelection
set
_currentSelection = newValue
mainPicker.reloadAllComponents()
textField_0.text = shapeOptions[_currentSelection]
textField_1.text = shape1[_currentSelection][0]
textField_2.text = shape2[_currentSelection][0]
override func viewDidLoad()
super.viewDidLoad()
currentSelection = 0;
@IBAction func btn1Clicked(_ sender: Any)
mainPicker.delegate = self
mainPicker.dataSource = self
mainPicker.tag = 0
mainPicker.isHidden = false
@IBAction func btn2Clicked(_ sender: Any)
mainPicker.delegate = self
mainPicker.dataSource = self
mainPicker.tag = 1
mainPicker.isHidden = false
func numberOfComponents(in pickerView: UIPickerView) -> Int
return 1
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
if pickerView.tag == 0
return shapeOptions.count
else if pickerView.tag == 1
return shape1[currentSelection].count
else
return shape2[currentSelection].count
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?
if pickerView.tag == 0
return shapeOptions[row]
else if pickerView.tag == 1
return shape1[currentSelection][row]
else
return shape2[currentSelection][row]
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
if pickerView.tag == 0
currentSelection = row
textField_0.text = shapeOptions[row]
textField_0.resignFirstResponder()
else if pickerView.tag == 1
textField_1.text = shape1[currentSelection][row]
textField_1.resignFirstResponder()
else
textField_2.text = shape2[currentSelection][row]
textField_2.resignFirstResponder()
【问题讨论】：
你能详细解释一下吗？您有三个按钮可以更改pickerView 的选择吗？当我点击 button3 时会发生什么？ @rs7 例如：BUTTON1（人类、动物、植物）； BUTTON2（人类：美国、欧洲、亚洲）；动物：（狗、猫、爬行动物）；植物：（水果、蔬菜、肉类）； BUTTON3（美式：男、女）；欧洲的...;亚洲...;狗（狼、鬣狗、狐狸）；猫（老虎、狮子、猎豹）；爬行动物...我希望我的解释很清楚:-D 或者这可能会帮助link 所以首先假设您在pickerView 中看到了一个由[人类、动物、植物] 组成的选择。您选择人类并点击 button1，然后 pickerView 选择更改为 [American, European, Asian]。您选择欧洲并点击按钮 2，现在选择变为 [男性，女性]。最后，您使用按钮 3 进行最后选择。我理解对了吗？如果是，为什么需要 3 个不同的按钮？它们会一个接一个地出现吗？ @rs7 点击Button1时pickerview会显示[human, animals, 植物]，然后点击Button2pickerview会显示[American, European, Asian]，然后点击Button3pickerview会显示[男，女]...每个按钮都有自己的标签，这就是需要它的原因。在我的脚本中，Button1 和 Button2 运行良好，但在 Button3 上却不行。 【参考方案1】：几件事：
您的代码中缺少Button3 函数。 您无需在每次单击按钮时设置pickerview 委托/数据源。 如果我正确理解您想要的内容，您无需在每次按下按钮时都取消隐藏 pickerView。只需在按下第一个按钮时取消隐藏即可。 我不确定 textField 的作用，但请考虑将 textField 代码移动到按钮函数中。 我在下面修改了您的代码。您只想在点击按钮以确认选择时重新加载 pickerView。您在代码中所做的是每次用户更改选择器选择时重新加载 pickerView。 （可选）您可以使用带有 didSet 块的 pickerViewIndex 变量来重新加载pickerView，而不是使用标签。在函数内部，您无需为 pickerView.tag 赋值，而是为 pickerViewIndex 赋值。
var currentSelection: Int
get
return _currentSelection
set
_currentSelection = newValue
// Consider moving the code below to the buttons functions
textField_0.text = shapeOptions[_currentSelection]
textField_1.text = shape1[_currentSelection][0]
textField_2.text = shape2[_currentSelection][0]
override func viewDidLoad()
super.viewDidLoad()
currentSelection = 0;
mainPicker.delegate = self
mainPicker.dataSource = self
@IBAction func btn1Clicked(_ sender: Any)
mainPicker.tag = 0
mainPicker.isHidden = false
mainPicker.reloadAllComponents()
@IBAction func btn2Clicked(_ sender: Any)
mainPicker.tag = 1
mainPicker.reloadAllComponents()
@IBAction func btn3Clicked(_ sender: Any)
mainPicker.tag = 2
mainPicker.reloadAllComponents()
func numberOfComponents(in pickerView: UIPickerView) -> Int
return 1
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
if pickerView.tag == 0
return shapeOptions.count
else if pickerView.tag == 1
return shape1[currentSelection].count
else
return shape2[currentSelection].count
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?
if pickerView.tag == 0
return shapeOptions[row]
else if pickerView.tag == 1
return shape1[currentSelection][row]
else
return shape2[currentSelection][row]
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
if pickerView.tag == 0
currentSelection = row
textField_0.text = shapeOptions[row]
textField_0.resignFirstResponder()
else if pickerView.tag == 1
currentSelection = row
textField_1.text = shape1[currentSelection][row]
textField_1.resignFirstResponder()
else
currentSelection = row
textField_2.text = shape2[currentSelection][row]
textField_2.resignFirstResponder()
【讨论】：
首先，我要感谢您花时间编写代码。我很感激。但是还没有满足button3部分。 [选项1：“圆形”：[“X”，“Y”，“Z”]] [选项2：“方形”：[“X”，“Y”，“Z”]，“椭圆”：[“A ", "B", "C"], "矩形": ["1", "2", "3"]] [选项 3: "三角形切割": ["X", "Y", "Z" ], "球体": ["A", "B", "C"]] 我没有设置合适的标签。我更新了我的答案。您需要将按钮 3 函数的第一行从 mainPicker.tag = 1 更改为 mainPicker.tag = 2，这样就可以了。 我发布了答案。感谢您的所有回复。我很感激。现在，我需要的下一个帮助是根据选择从列中的 CSV 文件中获取值。【参考方案2】：@rs7 我能从某人那里得到答案，这就是我正在寻找的答案：
private var shapeOptions = ["Option 1", "Option 2", "Option 3"]
private var shape = [["Round"],
["Square", "Oval", "Rectangle"],
["Triangle", "Sphere"]]
private var sizeA:[[String]] = [["X", "Y", "Z"]]
private var sizeB:[[String]] = [["A", "B", "C"]]
private var sizeC:[[String]] = [["1", "2", "3"]]
private var sizes:[[[String]]]?
var currentTypeSelection: Int?
didSet
mainPicker.reloadAllComponents()
var currentSizeSelection: Int?
didSet
mainPicker.reloadAllComponents()
override func viewDidLoad()
super.viewDidLoad()
self.sizes = [sizeA, sizeB, sizeC]
currentTypeSelection = 0;
currentSizeSelection = 0;
@IBAction func btn1Clicked(_ sender: Any)
mainPicker.delegate = self
mainPicker.dataSource = self
mainPicker.tag = 0
mainPicker.isHidden = false
@IBAction func btn2Clicked(_ sender: Any)
mainPicker.delegate = self
mainPicker.dataSource = self
mainPicker.tag = 1
mainPicker.isHidden = false
@IBAction func btn3Clicked(_ sender: Any)
mainPicker.delegate = self
mainPicker.dataSource = self
mainPicker.tag = 2
mainPicker.isHidden = false
func numberOfComponents(in pickerView: UIPickerView) -> Int
return 1
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
if pickerView.tag == 0
return shapeOptions.count
else if pickerView.tag == 1
return shape[currentTypeSelection!].count
else
return sizes![currentTypeSelection!][currentSizeSelection!].count
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?
if pickerView.tag == 0
return shapeOptions[row]
else if pickerView.tag == 1
return shape[currentTypeSelection!][row]
else
return sizes![currentTypeSelection!][currentSizeSelection!][row]
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
if pickerView.tag == 0
currentTypeSelection = row
textField_0.text = shapeOptions[row]
textField_0.resignFirstResponder()
currentSizeSelection = 0
else if pickerView.tag == 1
currentSizeSelection = row
textField_1.text = shape[currentTypeSelection!][row]
textField_1.resignFirstResponder()
else
textField_2.text = sizes![currentTypeSelection!][currentSizeSelection!][row]
textField_2.resignFirstResponder()
【讨论】：
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