TableViewCell scroll selects wrong cells when scrolling - ios

Question

My tableview highlights the wrong cells when I scroll up and down. In didSelectRowAtIndexPath, I'm trying to add the .Checkmark accessory view as well as change the font of cell.textLabel?.text. Upon scrolling, random rows are selected and the ones I manually select sometimes deselect.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("MyCell", forIndexPath: indexPath) as! MyCell
cell.textLabel?.text = self.array[indexPath.row]
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
var cell: UITableViewCell = tableView.cellForRowAtIndexPath(indexPath)!
if cell.accessoryType == UITableViewCellAccessoryType.Checkmark {
cell.accessoryType = .None
cell.textLabel!.font = UIFont(name: "HelveticaNeue", size: 16)
tableView.deselectRowAtIndexPath(indexPath, animated: true)
} else if cell.accessoryType == UITableViewCellAccessoryType.None {
cell.accessoryType = .Checkmark
cell.textLabel!.font = UIFont(name: "HelveticaNeue-Bold", size: 16)
}
tableView.deselectRowAtIndexPath(indexPath, animated: true)
}

Answer 1

Declare array which will keep track of which rows are selected:
var selectedRows:[Bool] = []
You need to make sure that it is populated with the same number of items as your data array.
Then modify your cellForRowAtIndexPath:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("MyCell", forIndexPath: indexPath) as! MyCell
cell.textLabel?.text = self.array[indexPath.row]
if selectedRows[indexPath.row] {
// row selected
cell.accessoryType = .Checkmark
}
else {
cell.accessoryType = .None
}
return cell
}
And in your didSelectRow function add line:
selectedRows[indexPath.row] = !selectedRows[indexPath.row]
When you modify your cell from didSelectRow the next time cell is dequeued it will have the accessory type which you set. The reason why it happens after scroll is because when you scroll the cells which become visible get dequeued. So, you need to manually set correct accessory type for them