Change Background of UICollectionView Cell on Tap

Question

I have a UICollectionView that I have created programmatically. I would like for the collection view to behave in the following way:

1. User touches cell 2. Cell background color changes 3. User releases touch 4. Cell background color changes 

This should be a quick color change that happens just before the selector related to the tap action is executed in which the viewcontroller containing the collection view is popped off the stack.

I have been looking at this question: UICollectionView cell change background while tap

in which there is the following summary of methods to use for this purpose:

// Methods for notification of selection/deselection and highlight/unhighlight events. // The sequence of calls leading to selection from a user touch is: // // (when the touch begins) // 1. -collectionView:shouldHighlightItemAtIndexPath: // 2. -collectionView:didHighlightItemAtIndexPath: // // (when the touch lifts) // 3. -collectionView:shouldSelectItemAtIndexPath: or -    collectionView:shouldDeselectItemAtIndexPath: // 4. -collectionView:didSelectItemAtIndexPath: or -collectionView:didDeselectItemAtIndexPath: // 5. -collectionView:didUnhighlightItemAtIndexPath: 

I am assuming I only need to implement one of the above methods from 'when touch begins' and 'when touch ends.' But no matter what I do, it appears that a background color changes and then remains changed. Here is an example of something I attempted which did not work:

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath  {    //pop vc   }  - (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath {   UICollectionViewCell* cell = [collectionView cellForItemAtIndexPath:indexPath];   cell.contentView.backgroundColor = [UIColor redColor]; }  - (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {   UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];   cell.contentView.backgroundColor = [UIColor greenColor]; } 

This results in the cell background color being changed only to red. I also looked at this question: UICollectionView Select and Deselect issue and tried implementing [UICollectionView selectItemAtIndexPath:animated:scrollPosition:] and calling it inside of didSelectItemAtIndexPath, but this did not work either. Collection view data source and delegate are set.

Answer 1

The problem is that you are changing the color on highlight and changing it back on deselect instead that on unhighlight

You should simply change this:

- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {   UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];   cell.contentView.backgroundColor = [UIColor greenColor]; } 

to this:

- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath {   UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];   cell.contentView.backgroundColor = [UIColor greenColor]; } 

Also, if you don't want to wait a bit before getting your highlight happen you should set the delaysContentTouches property of the collection view to NO

Edit: also ensure that you call

[collectionView deselectItemAtIndexPath:indexPath animated:NO]; 

inside the -didSelectItemAtIndexPath method

Answer 2

Swift 3 version

Add the following two methods to your view controller class:

// change background color when user touches cell func collectionView(_ collectionView: UICollectionView, didHighlightItemAt indexPath: IndexPath) {     let cell = collectionView.cellForItem(at: indexPath)     cell?.backgroundColor = UIColor.red }  // change background color back when user releases touch func collectionView(_ collectionView: UICollectionView, didUnhighlightItemAt indexPath: IndexPath) {     let cell = collectionView.cellForItem(at: indexPath)     cell?.backgroundColor = UIColor.green } 

See here for help in setting up a basic collection view in Swift.