How to change the title of a button inside a cell Swift - ios

Question

I have a collection view and inside a button.
When I tap this button I want to change its name.
I managed to do it but when I tap it, it changes if I have 20 buttons 10 of them like this if I tap the first button it changes the 0,2,4,6,8 and if I tap a button which isn't in the list then all buttons are checked.
This is my code:
#IBAction func following(sender: AnyObject) {
if follow.tag == sender.tag {
follow.setTitle("Following", forState: .Normal)
}
print("\(follow.tag) \(sender.tag)")
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Interest Cell", forIndexPath: indexPath) as! ThirdTabCell
cell.follow.tag = indexPath.row
return cell
}
Inside button's function I tried without if statement too but again the same problem.
When I print the tags it prints only the button which was tapped.
I also tried this to my ViewController
cell.follow.addTarget(self, action: #selector(ThirdTab.follow(_:)), forControlEvents: UIControlEvents.TouchUpInside)
//inside cellForItemAtIndexPath
func follow(sender:UIButton!) {
}

Answer 1

Just a short overview, So you get your answer
UICollectionView is highly optimized, and thus only keep On-screen visible rows in memory. Now, All rows Cells are cached in Pool and are reused and not regenerated. Whenever, user scrolls the UICollectionView, it adds the just-hidden rows in Pool and reuses them for next to be visible rows.
So, now, coming to your answer
When you tap on button, its title will get updated, but when you will scroll your collection view, the same cell with "updated button text" will be reused and that will cause the issue you are seeing.
SOLUTION
SAVE button state in an array, in your action method
#IBAction func following(sender: AnyObject) {
if follow.tag == sender.tag {
array[sender.tag] = "<text>"
collectionView.reloadData()
}
print("\(follow.tag) \(sender.tag)")
}
and inside your datasource method
update your button text like below:
//trick is to update your button text for each index
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell{
//SAMPLE CODE
let buttonValue = array[indexPath.index]
// update button value for each index
//trick is to update your button text for each index
cell.button.setTitle("", forState: .Normal)
}

Answer 2

Please change below the set title line in following function.
Existing Line:
follow.setTitle("Following", forState: .Normal)
New Line:
follow.setTitle("Following", forState: UIControlState.Normal)
Hope this is working for you.
Thanks

Answer 3

I would suggest you to approach it this way.
Inside cellForItemAtIndexPath you can assign a buttons outlet like this
cell.followOutlet.tag = indexPath.row
and then inside your follow function you can do this
#IBAction func following(sender: AnyObject) {
let follow = sender as! UIButton
let indexP = NSIndexPath(forRow: follow.tag, inSection: 0)
let cell = yourCollectionView.cellForItemAtIndexPath(indexP) as! yourCellName
follow.setTitle("Following", forState: .Normal)
}
And now you can do whatever you want with your button.