将选定行的索引传递给另一个 ViewController

Question

我有一个关于将索引 (myIndex) 从 TableView 传递到另一个 ViewController 的问题。 我已经发布了下面的代码。好消息：当我运行代码时，一个索引被传递给另一个 Viewcontroller。坏消息：这不是我预期的指数。 （当我在 Viewcontroller 中使用 TableView 打印出 myindex 时，一切正常。如果我将 myIndex 传递给另一个 ViewController，则索引会混淆...

目标：我的 TableView 包含 18 行（每个孔一行）。当我单击一行时，将打开另一个 Viewcontroller。在此 VieController 中，所选行的名称应显示在顶部。 我的想法是将每一行的索引传递给另一个 Viewcontroller，但这不能正常工作。

谁能帮帮我？

import UIKit
var holes = ["Hole 1","Hole 2","Hole 3","Hole 4","Hole 5","Hole 6","Hole 7","Hole 8", "Hole 9","Hole 10","Hole 11","Hole 12","Hole 13","Hole 14","Hole 15","Hole 16","Hole 17","Hole 18"]
var myIndex = 0

class OverViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    
    // Label
    @IBOutlet weak var BackButton: UIButton!
    @IBOutlet weak var ScoreButton: UIButton!
    @IBOutlet weak var OverviewLabel: UILabel!
    

    @IBOutlet weak var tableView: UITableView!
    

    override func viewDidLoad() {
           super.viewDidLoad()
    }
    
    
    @IBAction func BackToStartScreen(_ sender: UIButton) {
        performSegue(withIdentifier: "BackToStart", sender: self)
    }
    
    @IBAction func GoToResultScreen(_ sender: UIButton) {
        performSegue(withIdentifier: "GoToResult", sender: self)
    }
    
        
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            return holes.count
    }
        
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
            let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
            cell.textLabel?.text = holes[indexPath.row]
            return cell
    }
    
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        myIndex = indexPath.row
        performSegue(withIdentifier: "GoToScore", sender: self)
        
    }
  
}

还有 ScoreViewController：

import UIKit



class ScoreViewController: UIViewController {
    var score = 0
    var fairwayhits = 0
    var greeninregulation = 0
    var putts = 0
    var text = ""
        
    // Variable Deklaration
    var CurrentScore = 0
    var CurrentFairwayHits = 0
    var CurrentGreenInRegulations = 0
    var CurrentPutts = 0

    
    
    // Bar Label
    @IBOutlet weak var BackLabel: UIButton!
    @IBOutlet weak var TitleLabel: UILabel!
    
    // Score Elements
    @IBOutlet var ScoreLabel: UILabel!
    @IBOutlet var ScoreStepper: UIStepper!
    @IBOutlet var ScoreResultLabel: UILabel!
    @IBOutlet var ScoreFrameLabel: UILabel!
    
    // Fairway Elements
    @IBOutlet var FairwayLabel: UILabel!
    @IBOutlet var FairwaySwitch: UISwitch!
    @IBOutlet var FairwayResultLabel: UILabel!
    @IBOutlet var FairwayFrameLabel: UILabel!
    
    // Green Elements
    @IBOutlet var GreenLabel: UILabel!
    @IBOutlet var GreenSwitch: UISwitch!
    @IBOutlet var GreenResultLabel: UILabel!
    @IBOutlet var GreenFrameLabel: UILabel!
    
    // Putt Elements
    @IBOutlet var PuttLabel: UILabel!
    @IBOutlet var PuttStepper: UIStepper!
    @IBOutlet var PuttResultLabel: UILabel!
    @IBOutlet var PuttFrameLabel: UILabel!
    
    // Save Button
    @IBOutlet var SaveButton: UIButton!
    
    // Back Button
    @IBAction func BackButtonPressed(_ sender: UIButton) {
        performSegue(withIdentifier: "BackToOverview", sender: self)
    }
    
    // Score Stepper
    @IBAction func ScoreStepperPressed(_ sender: UIStepper) {
        ScoreResultLabel.text = Int(sender.value).description
    }
    
    // Fairway Switch
    @IBAction func FairwaySwitchPressed(_ sender: UISwitch) {
        if FairwaySwitch.isOn {
            CurrentFairwayHits = 1
            FairwayResultLabel.text = "X"
        } else {
            CurrentFairwayHits = 0
            FairwayResultLabel.text = "-"
        }
    }
    
    // Green Switch
    @IBAction func GreenSwitchPressed(_ sender: UISwitch) {
        if GreenSwitch.isOn {
            CurrentGreenInRegulations = 1
            GreenResultLabel.text = "X"
        } else {
            CurrentGreenInRegulations = 0
            GreenResultLabel.text = "-"
        }
    }
    

    // Putt Stepper
    @IBAction func PuttStepperPressed(_ sender: UIStepper) {
        PuttResultLabel.text = Int(sender.value).description
    }
    
    
    // Save Button
    @IBAction func SaveButtonPressed(_ sender: UIButton) {
        if Int(PuttResultLabel.text!)! >= Int(ScoreResultLabel.text!)! {
            showAlert()
        } else {
        score = score + Int(ScoreResultLabel.text!)!
        fairwayhits = fairwayhits + CurrentFairwayHits
        greeninregulation = greeninregulation + CurrentGreenInRegulations
        putts = putts + Int(PuttResultLabel.text!)!
        
        print(score)
        print(fairwayhits)
        print(greeninregulation)
        print(putts)
            
        performSegue(withIdentifier: "ShowResult", sender: self)
        }
    }
    
    
    func showAlert() {
        let alert = UIAlertController(title: "Ops, something went wrong", message: "The number of putts must be smaller than your score!", preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "Ok", style: .cancel, handler: { action in print("tapped Dismissed")}))
        
        present(alert, animated: true)
    }

    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if SaveButton.isTouchInside,
           let resultVC = segue.destination as? ResultViewController
            {

            CurrentScore = score /// get the current cell's text
            CurrentPutts = putts
            resultVC.score = resultVC.score + String((resultVC.ScoreResultLabel.text!))
            resultVC.fairway = String(fairwayhits)
            resultVC.green = String(greeninregulation)
            resultVC.putt = String(putts)
            
            
               }
    }
    
    

    override func viewDidLoad() {
        
        super.viewDidLoad()

        ScoreStepper.wraps = true
        ScoreStepper.autorepeat = true
        ScoreStepper.minimumValue = 1
        ScoreStepper.maximumValue = 20
        
        PuttStepper.wraps = true
        PuttStepper.autorepeat = true
        PuttStepper.minimumValue = 0
        PuttStepper.maximumValue = 20
        

        TitleLabel.text = text
    
    }
}

结果视图控制器：

class ResultViewController: UIViewController {
    
    var score = ""
    var fairway = ""
    var green = ""
    var putt = ""
    

    @IBOutlet weak var TitleLabel: UILabel!
    @IBOutlet weak var BackButton: UIButton!
    @IBOutlet weak var ShareButton: UIButton!
    
    // Score Label
    @IBOutlet weak var ScoreLabel: UILabel!
    @IBOutlet weak var ScoreResultLabel: UILabel!
    @IBOutlet weak var ScoreFrameLabel: UILabel!
    
    // Fairway Label
    @IBOutlet weak var FairwayLabel: UILabel!
    @IBOutlet weak var FairwayResultLabel: UILabel!
    @IBOutlet weak var FairwayFrameLabel: UILabel!
    
    // Green Label
    @IBOutlet weak var GreenLabel: UILabel!
    @IBOutlet weak var GreenResultLabel: UILabel!
    @IBOutlet weak var GreenFrameLabel: UILabel!
    
    // Putt Label
    @IBOutlet weak var PuttLabel: UILabel!
    @IBOutlet weak var PuttResultLabel: UILabel!
    @IBOutlet weak var PuttFrameLabel: UILabel!
    
    // Back Button Action
    @IBAction func BackButtonPressed(_ sender: UIButton) {
        performSegue(withIdentifier: "BackToOverview", sender: self)
        
    }


        
    override func viewDidLoad() {
        super.viewDidLoad()

        ScoreResultLabel.text = "\(score)"
        FairwayResultLabel.text = "\(fairway)"
        GreenResultLabel.text  = "\(green)"
        PuttResultLabel.text = "\(putt)"
        
        
    }
    

 

}

Answer 1

第一件事：你不想在类之外有变量。当然，您可以从所有课程中访问它们。但是，这不是好的做法，您会遇到状态错误。

所以，替换

var holes = ["Hole 1","Hole 2","Hole 3","Hole 4","Hole 5","Hole 6","Hole 7","Hole 8", "Hole 9","Hole 10","Hole 11","Hole 12","Hole 13","Hole 14","Hole 15","Hole 16","Hole 17","Hole 18"]
var myIndex = 0

class OverViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

与

class OverViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    var holes = ["Hole 1","Hole 2","Hole 3","Hole 4","Hole 5","Hole 6","Hole 7","Hole 8", "Hole 9","Hole 10","Hole 11","Hole 12","Hole 13","Hole 14","Hole 15","Hole 16","Hole 17","Hole 18"]
    var myIndex = 0

还有替换

var score = 0
var fairwayhits = 0
var greeninregulation = 0
var putts = 0

var text = ""

class ScoreViewController: UIViewController {

与

class ScoreViewController: UIViewController {
    var score = 0
    var fairwayhits = 0
    var greeninregulation = 0
    var putts = 0

    var text = ""

现在，我假设您想要这种行为：

1. 在表格视图中按一个单元格
2. 现在ScoreViewController 显示单元格的文本

你可以把它放在你的prepareForSegue func:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let selectedPath = tableView.indexPathForSelectedRow else { return }
    if 
        segue.identifier == "GoToScore",
        let scoreVC = segue.destination as? ScoreViewController
    {
        let currentText = holes[selectedPath.row] /// get the current cell's text
        scoreVC.text = currentText
    }
}

编辑：然后您可以将TitleLabel.text 设置为text 内的viewDidLoad 属性，如下所示：

class ScoreViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        TitleLabel.text = text /// right here!
    }   
}

您还应该将所有属性（包括TitleLabel 等插座）保持小写。这只是一种让其他人更容易阅读您的代码的约定。

@IBOutlet weak var backLabel: UIButton!
@IBOutlet weak var titleLabel: UILabel!

请记住，要更改出口的名称，您需要断开链接并从情节提要中重新链接。