对返回空数据的两个按钮使用相同的pickerView

Posted 2023-02-24

【中文标题】对返回空数据的两个按钮使用相同的pickerView

【英文标题】：Using same pickerView for two buttons returning empty data

【发布时间】：2019-04-01 12:03:22

【问题描述】：

这是我的代码。我正在尝试将UIPickerview 用于具有不同数据的几个按钮。但是当我运行我的项目时，它显示了我的空白灰色选择器视图。有人告诉我我必须重新加载pickerView，但我使用了它，例如“mainPV.delegate = self .....如果有人可以帮助我，请帮助我

import UIKit

class SearchBuyVC: UIViewController 

    @IBOutlet weak var optionV: UIView!

    @IBOutlet weak var doneBtn: UIButton!
    @IBOutlet weak var searchBtn: UIButton!

    // picker view
    @IBOutlet var mainPV: UIPickerView! // main
    @IBOutlet var secPV: UIPickerView! //type
    @IBOutlet var minPV: UIPickerView! //priceMin



    @IBOutlet weak var typeBtn: UIButton!

    @IBOutlet weak var PriceMinBtn: UIButton!

    var optionSelector = 0
    let searchData = ["Search by Areas", "Search by Map", "Search by LRT/MRTs", "Search by Schools", "Search by Propery Name"]

    let typeData = ["All Residental", "All Commerical"]
    let minNum = ["Any", "100 k", "200 k", "300 k", "400 k", "500 k", "600k ", "700 k"]

    override func viewDidLoad() 
        super.viewDidLoad()
        setUpNav(arrowType: 2)

       mainPV = UIPickerView()
       secPV = UIPickerView()
        minPV = UIPickerView()
       mainPV.delegate = self
        secPV.delegate = self
        minPV.delegate = self

        // Do any additional setup after loading the view.
    

    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        //Dispose of any resources that
    

    override func viewDidAppear(_ animated: Bool) 
        self.navigationController?.setNavigationBarHidden(false, animated: true)
    

    @IBAction func selectOptionsPressed(_ sender: Any) 

        openOptions()
        mainPV.delegate = self
        secPV.delegate = self
        minPV.delegate = self

    

    @IBAction func typeSelect(_ sender: Any) 
        openOptions()
        mainPV.delegate = self
        secPV.delegate = self
        minPV.delegate = self
    


    @IBAction func minPriceBtn(_ sender: Any) 
        openOptions()
        mainPV.delegate = self
        secPV.delegate = self
        minPV.delegate = self

    








    @IBAction func donePressed(_ sender: Any) 
        switch optionSelector 
        case 0:
            FiltersController.instance.showAreaFilter(nc: self.navigationController!)
        case 1:
            FiltersController.instance.showMapFilter(nc: self.navigationController!)
        case 2:
            FiltersController.instance.showTrainStations(nc: self.navigationController!)
        case 3:
            FiltersController.instance.showSchoolFilter(nc: self.navigationController!)
        default:
            FiltersController.instance.showNameFilter(nc: self.navigationController!)
        
        closeOptions()
    

    func openOptions() 
        optionV.isHidden = false
        mainPV.isHidden = false
        minPV.isHidden = false
        doneBtn.isHidden = false
        secPV.isHidden = false
    

    func closeOptions()
        optionV.isHidden = true
        mainPV.isHidden = true
        minPV.isHidden = true
        doneBtn.isHidden = true
        secPV.isHidden = true
    

    @IBAction func nextPressed(_ sender: Any) 
        ListingController.instance.showBuyListing(nc: self.navigationController!)
    


extension SearchBuyVC: UIPickerViewDelegate, UIPickerViewDataSource 


    func numberOfComponents(in pickerView: UIPickerView) -> Int 
        return 1
    

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



        if pickerView == mainPV 
            return searchData.count
        

        return 1
    

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? 
        if pickerView == mainPV
            return searchData[row]
        
        if pickerView == secPV
            return typeData[row]

        
        if pickerView == minPV
            return minNum[row]
        
        return ""
    

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) 
        optionSelector = row
        if pickerView == mainPV
            searchBtn.setTitle(searchData[row], for: .normal)
        
        if pickerView == secPV
            typeBtn.setTitle(typeData[row], for: .normal)
        

        if pickerView == minPV
            PriceMinBtn.setTitle(minNum[row], for: .normal)

        
    

【问题讨论】：

mainPV = UIPickerView() secPV = UIPickerView() minPV = UIPickerView() 删除所有这些导致加载空视图和 mainPV.dataSource = self secPV.dataSource = self minPV.dataSource = self 这将显示选择器查看每个中的所有数据

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int if pickerView == mainPV return searchData.count if pickerView == secPV return typeData.count if pickerView = = minPV 返回 minNum.count 返回 1 。为每个选择器视图清楚地传递每个数据

【参考方案1】：

还需要为pickerViews设置dataSource。这样UIPickerViewDataSource的方法就会被调用，负责将所有数据返回给UIPickerView。你的班级必须确认UIPickerViewDataSource 协议。

例如：

picker_country.dataSource = self

【参考方案2】：

首先将类中的 UIPickerView 协议导入为，

class SearchBuyVC: UIViewController  UIPickerViewDelegate, UIPickerViewDataSource

并添加以下行来调用数据源函数，

mainPV.delegate = self
secPV.delegate = self
minPV.delegate = self
mainPV.dataSource = self
secPV.dataSource = self
minPV.dataSource = self