UICollectionView - didDeselectItemAtIndexPath not called if cell is selected
The issue is, that the cell is selected, but the UICollectionView
does not know anything about it. An extra call for the UICollectionView
solves the problem:
[collectionView selectItemAtIndexPath:indexPath animated:NO scrollPosition:UICollectionViewScrollPositionNone];
Full code:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
cell.selected = YES;
[collectionView selectItemAtIndexPath:indexPath animated:NO scrollPosition:UICollectionViewScrollPositionNone];
return cell;
}
I keep the question to help someone who may face the same problem.
I think the solution @zeiteisen provided is a way around solution. The actual thing lies in the selection mode. There is nothing to be set the in property cell.selected
.
There are two properties of the UICollectionView
name allowsMultipleSelection
and allowsSelection
.
allowsMultipleSelection
is NO
by default and allowsSelection
is YES
.
If you want to select only one cell then the code @the initialization look like
yourCollectionView.allowsMultipleSelection = NO;
yourCollectionView.allowsSelection = YES; //this is set by default
Then the settings will allow you select only one cell at a time, not less not more. You must have to select at least one cell. The didDeselectItemAtIndexPath
wont be called unless you select another cell. Tapping an already selected UICollectionViewCell
won't make it to Deselect. This is the policy behind the implementation.
If you want to select multiple cell then the code @the initialization should look like the following:
yourCollectionView.allowsMultipleSelection = YES;
yourCollectionView.allowsSelection = YES; //this is set by default
Then the settings will allow to select multiple cell. This settings allow none or multiple UICollectionViewCell
to be selected. Number of cell selected will be
0 <= number_selected_cell <= total_number_of_cell
This is the policy behind the multiple cell selection.
If you are intended to use any of the above you are welcome to use apples api without extra headache, otherwise you got to find a way around to sneak into your goal using your own code or apple's api.
I had the same issue. I pre-selected cells upon table load yet I had to double tap a cell to deselect it. @zeiteisen answer helped me. However, I'm working in Swift 3 so I thought I'd give an answer in Swift.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! Cell
if /*Test for Selection*/ {
cell.isSelected = true
collectionView.selectItem(at: indexPath, animated: false, scrollPosition: .left)
}
return cell
}