didSelectItemAt for UICollectionView is only calling on double touch

Question

I'm facing a weird issue in UICollectionView using iOS11 emulator. In my project i have a UICollectionView with UIImageView as cells and I've created segue as Triggered Segues for cells by dragging it to a view controller. It was working great but know the segue is not performing so i decided to remove the segue from cells Triggered Segues and I created a segue from my view controller to the destination view controller and performed segue from code

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PhotoCell", for: indexPath) as! PhotoCell
    if let url = URL(string: "\(StringResources.serverAddress)/Content/images/Files/Thumb/\(photos[indexPath.row])") {
        cell.image.downloadFrom(url: url)
    }
    return cell
}

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    print("clicked")
    performSegue(withIdentifier: "PhotoSegue", sender: collectionView.cellForItem(at: indexPath))
}

but it's not working either and there is no clicked printed in console. I've checked cell and UIImageView user interaction also UICollectionView delegate is ok. How can i fix it?

edit: I've found the problem. It's only calling when I'm double clicking on cell

yes I've mentioned that it has been set to my view controller and i did it again in code but didn't help @OzgurVatansever — Amir_P, Oct 25 '17 at 14:24
is it a `UIImageView` or a `UICollectionViewCell` with an `UIImageView` inside? — jvrmed, Oct 25 '17 at 14:26
Post your `collectionView(_:cellForItemAt:)` code. Also, in your view controller's `viewDidAppear(_:)` method, add code `print("collection view data source = " + myCollectionView.dataSource)` and check what is displayed. — Duncan C, Oct 25 '17 at 14:26
As stated by @OzgurVatansever make sure you have your delegate and datasource set also you will need `override` in front of your function as well. — MwcsMac, Oct 25 '17 at 14:27
it's a `UICollectionViewCell` with a `UIImageView` inside @jvrmed — Amir_P, Oct 25 '17 at 14:28
I've edited my question and the output is my view controller @DuncanC — Amir_P, Oct 25 '17 at 14:31
is it possible to scroll your collectionView? Is there any custom UIGestureRecognizer over your view or cell? — jvrmed, Oct 25 '17 at 14:31
there is no need to override and when I'm adding it shows me an error @MwcsMac — Amir_P, Oct 25 '17 at 14:32
is your `downloadFrom` method performed in a background thread? the download could be blocking the UI — jvrmed, Oct 25 '17 at 14:33
yes it's using `URLSession.shared.dataTask` for download @jvrmed — Amir_P, Oct 25 '17 at 14:35
did you set the delegate of the CollectionView in the storyboard as the File's owner? — tonik12, Oct 25 '17 at 14:53
@Amir_P You should answer your own question and then accept it as soon as you're allowed so that your readers can learn the solution. — Duncan C, Oct 25 '17 at 16:49
i couldn't foul the solution. i just found the problem @DuncanC — Amir_P, Oct 25 '17 at 18:21
@Amir_P What is the fix for this. I m facing this issue too. — Rajesh, Nov 11 '18 at 14:24
I'm not sure if our cases are similar but for me the problem was that I was adding an `UITapGestureRecognizer` to the whole view to dismiss the keyboard and removing that fixed the problem @Rajesh — Amir_P, Nov 11 '18 at 16:14

score 9 · Accepted Answer · answered Oct 25 '17 at 14:56

9

There are some things that you could check and once all of them are in order it should work:

Check that your UICollectionView has both delegate and dataSource set.
Check that your UIImageView userInteractionEnabled property is set to false.

According to documentation:

Image views ignore user events by default. Normally, you use image views only to present visual content in your interface. If you want an image view to handle user interactions as well, change the value of its isUserInteractionEnabled property to true. After doing that, you can attach gesture recognizers or use any other event handling techniques to respond to touch events or other user-initiated events.

Check that both UICollectionView and parent have. userInteractionEnabled property is set to true.
Check that there are no other UIGestureRecognizers catching your touch event.
Check that there are no network requests freezing your UI.

Considering the information that you provided, I would try to remove the UIImageView from the cell and make sure that the cell touch is working before adding more elements.

answered Oct 25 '17 at 14:56

jvrmed

834
6
12

it's not working. I've edited my post please read the last line – Amir_P Oct 25 '17 at 15:37
you need to share more information, your cell class and possibly your controller too, there is another element that is interfering in your views for sure – jvrmed Oct 25 '17 at 15:38
is there any other _UICollectionViewDelegate_ method that you are implementing? – jvrmed Oct 25 '17 at 15:45
no it's only section and item in section the cell for item and did select item – Amir_P Oct 25 '17 at 15:46
check this https://stackoverflow.com/questions/26351819/ios-uitableviewcell-needs-to-be-pressed-twice-to-call-didselectrowatindexpath – jvrmed Oct 25 '17 at 15:50
by double click i mean multi touch click @jvrmed – Amir_P Oct 25 '17 at 18:23

Amir_P · Answer 2 · 2021-01-27T14:46:50.057

3

the problem is that I was adding a UITapGestureRecognizer to dismiss the keyboard and that was catching touch events.

func hideKeyboardWhenTappedAround() {
    let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
    view.addGestureRecognizer(tap)
}

edited Jan 27 '21 at 14:46

answered Oct 26 '17 at 07:49

Amir_P

8,322
5
43
92

1

told you there was another `UITapGestureRecognizer` blocking your events on item number 5 of my answer – jvrmed Oct 26 '17 at 13:24
yes you were right sorry i forgot to accept answer @jvrmed – Amir_P Oct 26 '17 at 13:25
Finally, This should be the accepted solution. – Shanu Singh Jan 27 '21 at 12:33

Haas · Answer 3 · 2020-11-12T16:06:16.340

1

The issue could be due to the fact that collection views have a didSelectItemAt method as well as a didDeselectItemAt method which alternate per click. This could explain why it only works on a double click (one click calls didSelect, the next calls didDeselect).

A quick (but not elegant) solution could be to implement your didDeselectItemAt and just use it to call the didSelectItemAt

edited Nov 12 '20 at 16:06

answered Jul 30 '18 at 11:16

Haas

11
4

didSelectItemAt for UICollectionView is only calling on double touch

3 Answers3