从 ViewController Swift 中的 UITableViewCell 调用 function

Question

I need to call function deleteButtonShowHide , which is in TeamsCell, from TeamsVC, when plusBtnTapped . I am trying to figure it out with protocol TeamsVCDelegate , but it doesn't work( It works vice versa for me. But I do not know how to implement something like cell.teamsCellDelegate = self

TeamsCell

import UIKit

protocol TeamsCellDelegate {
    func deleteCell()
}



class TeamsCell: UITableViewCell {
    
    @IBOutlet weak var teamNameLbl: UILabel!
    @IBOutlet weak var deleteButton: UIButton!
    var teamsCellDelegate: TeamsCellDelegate?
    
    
    override func awakeFromNib() {
        super.awakeFromNib()
    }
    
    
    func updateCell(team: team) {
        teamNameLbl.text = team.name
    }
    
    
    @IBAction func deleteButtonTapped(_ sender: Any) {
        debugPrint("delet tapped")
        //deleteButtonShowHide()
        findAndDeleteTeam()
        teamsCellDelegate?.deleteCell()
    }
    
    func findAndDeleteTeam() {
        for i in 0...teams.count - 1 {
            if teams[i].name == teamNameLbl.text {
                teams.remove(at: i)
                break
            }
        }
    }
    
    func deleteButtonShowHide(){
        if teams.count < 3 {deleteButton.isHidden = true}
        if teams.count > 2 {deleteButton.isHidden = false}
    }
    
}

extension TeamsCell: TeamsVCDelegate {
    func deleteButtonSH() {
        debugPrint("XXX")
        deleteButtonShowHide()
    } 
}

TeamsVC

import UIKit

protocol TeamsVCDelegate {
    func deleteButtonSH()
}

class TeamsVC: UIViewController, UITableViewDelegate, UITableViewDataSource {
   
    @IBOutlet weak var plusBtn: UIButton!
    @IBOutlet weak var teamsTable: UITableView!
    var teamsVCDelegate: TeamsVCDelegate?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        teamsTable.delegate = self
        teamsTable.dataSource = self
        teamsTable.rowHeight = 55
        teamsTable.isScrollEnabled = false
        teamsTable.backgroundColor = nil
        teamsTable.separatorStyle = .none
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return teams.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if let cell = tableView.dequeueReusableCell(withIdentifier: "TeamsCell") as? TeamsCell {
            cell.updateCell(team: teams[indexPath.row])
            cell.teamsCellDelegate = self
            return cell
        }
        return UITableViewCell()
    }
    
    @IBAction func plusBtnTapped(_ sender: Any) {
        plusBtnHide()
        addTeam()
        teamsTable.reloadData()
        teamsVCDelegate?.deleteButtonSH()
        print(teams)
    }
    
    func plusBtnShow() {
        if teams.count < 5 {plusBtn.isHidden = false}
    }
    
    func plusBtnHide() {
        if teams.count == 4 { plusBtn.isHidden = true}
    }
    
}

extension TeamsVC: TeamsCellDelegate {
    func deleteCell() {
        self.teamsTable.reloadData()
        self.plusBtnShow()
    }
}

Answer 1

You could call deleteButtonShowHide function when you are loading/setting up a cell:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if let cell = tableView.dequeueReusableCell(withIdentifier: "TeamsCell") as? TeamsCell {
        cell.updateCell(team: teams[indexPath.row])
        cell.deleteButtonShowHide()  // <-- HERE
        cell.teamsCellDelegate = self
        return cell
    }
    return UITableViewCell()
}

---

By the way, your cell should not contain such logic in the first place. It should depend on some data model object which then should be used to setup your cell correctly (show/hide UI elements, etc.).

Answer 2

You could simplify by setting the button show/hide when computing the number of row.

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    if teams.count < 5 {plusBtn.isHidden = false}
    if teams.count == 4 { plusBtn.isHidden = true}
    return teams.count
}

And set the delebutton visibility when creating the cell:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if let cell = tableView.dequeueReusableCell(withIdentifier: "TeamsCell") as? TeamsCell {
        cell.updateCell(team: teams[indexPath.row])
        // cell.teamsCellDelegate = self
        cell.deleteButton.isHidden = (teams.count < 3)
        return cell
    }
    return UITableViewCell()
}

So no need for delegate and cell does not have to know about the model (teams)