update a cell in tableview - ios

Question

My code reads cities array to a tableView.
When a cell is clicked, it move to a SecondViewController. The SecondViewController has a button.
If I clicked the button, it will display an image into that cell.
Problem: I am trying to update the cell whenever the button is clicked. It is working but no matter which cell is clicked, it always displays the image for cell 3, if I clicked again it displays for cell number 1 image.
How to fix this so that when the button is clicked, it display the image for it's cell and if the same cell is clicked, hide the image.
My codes:
var first = 0
var reload = false
var cellNumber: Int!
var cities:[String] = ["paris", "moscow", "milan","rome","madrid","garda","barcelona"]
#IBOutlet weak var tableView: UITableView!
// func to reload a cell
#objc func toReload(rowNumber: Int){
reload = true
let indexPath = IndexPath(row: rowNumber , section: 0)
tableView.reloadRows(at: [indexPath], with: .none)
}
// load tableview from a SecondViewController call
#objc func loadList(notification: NSNotification){
self.tableView.reloadData() // reload tableview
toReload(rowNumber: cellNumber)
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cities.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! CustomCell
cell.label1.text = cities[indexPath.row]
let image : UIImage = UIImage(named: "20870718")! // assign imageView to an image
if first == 0 {
cell.myimage.isHidden = true // hide image
first = 1 // condition to never enter again
}
if reload == true {
if cell.myimage.isHidden == true {
cell.myimage.image = image
cell.myimage.isHidden = false
}
else{
cell.myimage.isHidden = true
}
reload = false
}
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
self.cellNumber = indexPath.row
performSegue(withIdentifier: "send", sender: self)
}
override func viewDidLoad() {
super.viewDidLoad()
tableView.reloadData()
NotificationCenter.default.addObserver(self, selector: #selector(loadList), name: NSNotification.Name(rawValue: "load"), object: nil)
// call load list method
}
}
SecondViewController:
#IBAction func displayImage(_ sender: Any) {
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "load"), object: nil)
}

Answer 1

There is a problem in your cellForRowAt.when secondViewController notify the first one no matter which cell you are reloading cellForRowAt always will be called because when you scroll tableView wants to recuse cell and reload == true becomes true for all cells.so you have to check if indexPath.row == cellNumber then do the rest work :
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! CustomCell
cell.label1.text = cities[indexPath.row]
let image : UIImage = UIImage(named: "20870718")! // assign imageView to an image
if first == 0 {
cell.myimage.isHidden = true // hide image
first = 1 // condition to never enter again
}
if indexPath.row == cellNumber {
if reload == true {
if cell.myimage.isHidden == true {
cell.myimage.image = image
cell.myimage.isHidden = false
}
else {
cell.myimage.isHidden = true
}
reload = false
}
}
return cell
}