增加/减少一个值并在TableViewCell Swift Xcode中的Label中显示结果

Question

I have a ViewController with a TableView and a TableViewCell containing multiple sections and rows. I have 2 button "plus" and "minus" and a label "totalLabel" in each row.

How can I get the value displayed in the label for each specific row when the user presses the + or - button?

for now when I run the app and press the + or - buttons only the totalLabel of the section 0/row 0 is working while random values just appear and disappear in the other sections/rows

my tableViewCell code :

import UIKit

protocol CommandeCellDelegate: class {
}

class CommandeCell: UITableViewCell {

weak var delegate : CommandeCellDelegate!

@IBOutlet weak var drinksLabel: UILabel!
@IBOutlet weak var priceLabel: UILabel!

@IBOutlet weak var totalLabel: UILabel!

@IBOutlet weak var plusButton: UIButton!
@IBOutlet weak var minusButton: UIButton!

override func awakeFromNib() {
    super.awakeFromNib()
}


override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)
}

}

here is my code for cellForRowAt :

class MenuViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, CommandeCellDelegate {

var count : Int = 0

var countValue : String!

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "CommandeCell", for: indexPath) as! CommandeCell

    cell.plusButton.tag = indexPath.section
    cell.plusButton.tag = indexPath.row
    cell.plusButton.addTarget(self, action: #selector(self.increaseValue), for: .touchUpInside)

    cell.minusButton.tag = indexPath.section
    cell.minusButton.tag = indexPath.row
    cell.minusButton.addTarget(self, action: #selector(self.decreaseValue), for: .touchUpInside)

    if indexPath.section == 0 {
        let softInfo = softs[indexPath.row]
        cell.drinksLabel?.text = softInfo.drinkName
        cell.totalLabel?.text = // how to display countValue here?

        let HappyHourStatus = partner!.barHHStatus
        if case "0" = HappyHourStatus {
            cell.priceLabel?.text = softInfo.drinkHHPrice
        } else
            if case "1" = HappyHourStatus {
                cell.priceLabel?.text = softInfo.drinkPrice
        }
    }

        else if indexPath.section == 1 {
        let cocktailInfo = cocktails[indexPath.row]
        cell.drinksLabel?.text = cocktailInfo.drinkName
        cell.totalLabel?.text = // how to display countValue here?

        let HappyHourStatus = partner!.barHHStatus
        if case "0" = HappyHourStatus {
            cell.priceLabel?.text = cocktailInfo.drinkHHPrice
        } else
            if case "1" = HappyHourStatus {
                cell.priceLabel?.text = cocktailInfo.drinkPrice
        }
    }
        return cell
}

and my funcs to increase or decrease the value :

func increaseValue(_ sender: UIButton) -> Int {

    count = 1 + count
    print(count)

    countValue = "\(count)"

    let rowToReload = IndexPath(row: sender.tag, section: sender.tag)
    let rowsToReload: [Any] = [rowToReload]
    tableView.reloadRows(at: rowsToReload as! [IndexPath], with: .automatic)

    return count
}

func decreaseValue(_ sender: UIButton) -> Int {

    if count == 0 {
        print("Count zero")
    } else {
        count = count - 1
    }

    countValue = "\(count)"

    let rowToReload = IndexPath(row: sender.tag, section: sender.tag)
    let rowsToReload: [Any] = [rowToReload]
    tableView.reloadRows(at: rowsToReload as! [IndexPath], with: .automatic)

    return count

}

I have tried countless solutions but so far none is working - thank you for your help!

Answer 1

So your problem is this code

cell.plusButton.tag = indexPath.section
cell.plusButton.tag = indexPath.row

A tag can only store one value. So you are overriding the section with the row. So it is going to cause all sorts of weirdness. The better solution is to determine what cell you are targeting based on the button itself. Since you know what button was clicked you can convert the location of this button to a point on the table view. And then that point to aa particular index path.

So using your example code you can do something like below:

var softsCount: [Int] = []
var cocktailsCount: [Int] = []

override func viewDidLoad() {
    super.viewDidLoad()

    softsCount = Array(repeating: 0, count: softs.count) // Fill an array with 0
    cocktailsCount = Array(repeating: 0, count: cocktails.count) // Fill an array with 0
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    ...
    if indexPath.section == 0 {
        ...
        cell.totalLabel?.text = "\(softsCount[indexPath.row])"
        ...
    } else if indexPath.section == 1 {
        ...
        cell.totalLabel?.text = "\(cocktailsCount[indexPath.row])"
        ...
    }
    ...
}

func increaseValue(_ sender: UIButton) {
    let pointInTable = sender.convert(sender.bounds.origin, to: tableView)
    if let indexPath = self.tableView.indexPathForRow(at: pointInTable), let cell = tableView.cellForRow(at: indexPath) {
        if indexPath.section == 0 {
            softsCount[indexPath.row] += 1
            cell.totalLabel?.text = "\(softsCount[indexPath.row])"
        } else if indexPath.section == 1 {
            cocktailsCount[indexPath.row] += 1
            cell.totalLabel?.text = "\(cocktailsCount[indexPath.row])"
        }
    }
}

No sure why you are returning count. I am sure this is just a partial implementation. But the button should take care of the entire action including updating the label with the new count. You don't normally return values from button presses.

So updated the example to update the label with the current count. Since I am unable to see what your drinks object I made an assumption that the drinks class has a count parameter that starts at 0. This way each individual drink has a count assigned to it.