How to change an image within UICollectionViewCell on tap? - ios

Question

I am trying to change an image that is displayed inside a UICollectionViewCell on tap. Here is my code:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"Cell" forIndexPath:indexPath];
UIImageView *cellImageView = (UIImageView *)[cell viewWithTag:100];
cellImageView.image = [[allActivities objectAtIndex:indexPath.row] obverseIcon];
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"%# was selected", [[allActivities objectAtIndex:indexPath.row] name]);
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"Cell" forIndexPath:indexPath];
UIImageView *cellImageView = (UIImageView *)[cell viewWithTag:100];
Activity *activity = [allActivities objectAtIndex:indexPath.row];
if (activity.isMy)
{
activity.isMy = NO;
cellImageView.image = [[allActivities objectAtIndex:indexPath.row] obverseIcon];
}
else
{
activity.isMy = YES;
cellImageView.image = [[allActivities objectAtIndex:indexPath.row] reverseIcon];
}
[allActivities replaceObjectAtIndex:indexPath.row withObject:activity];
[self.collectionView reloadData];
}
When I tap a cell, image does not change.

Answer 1

try this:
- (UICollectionViewCellSubclass *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCellSubclass *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"Cell" forIndexPath:indexPath];
Activity *activity = allActivities[indexPath.row];
cell.imageView.image = activity.isMy ? activity.obverseIcon : activity.reverseIcon;
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
Activity *activity = allActivities[indexPath.row];
activity.isMy = !activity.isMy;
[self.collectionView reloadItemsAtIndexPaths:#[indexPath]];
}
where UICollectionViewCellSubclass is your custom class which inherit from UICollectionViewCell and implement:
#property (nonatomic, strong) UIImageView *imageView;

Answer 2

Create custom cell class with super class UICollectionViewCell.
Create an outlet from your cell's image to that class .h file.
In your didSelectItemAtIndexPath method replace UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"Cell" forIndexPath:indexPath];
with your cell's class name.
Change the image. For example cell.imageView.hidden = YES;

Answer 3

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
questionImageCollectionViewCell * cell=[self.questionCollectionView dequeueReusableCellWithReuseIdentifier:#"coustomCell" forIndexPath:indexPath];
cell.optionImageView.image=[UIImage imageNamed:[_optionImageArr objectAtIndex:indexPath.item]];
[cell.rightTickImg setHidden:YES];
if(self.array==nil)
{
[cell.rightTickImg setHidden:YES];
}
else
{
[cell.rightTickImg setHidden:YES];
NSDictionary *dic = self.array[indexPath.row];
NSLog(#"ouput DIC=%#",dic);
NSLog(#"objeject for key=%#",[dic objectForKey:#"option"]);
// if ([dic[#"option"] boolValue])
if([[dic objectForKey:#"option"] isEqualToString:#"1"])
{
[cell.rightTickImg setHidden:NO];
}
else
{
[cell.rightTickImg setHidden:YES];
}
}
return cell;
}
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return
CGSizeMake(collectionView.frame.size.width/2.2,collectionView.frame.size.height/2.3);
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
[self dicData];
NSLog(#"First=%#",self.array);
[self.array removeObjectAtIndex:indexPath.row];
NSDictionary *dic = #{#"option":#"1"};
[self.array insertObject:dic atIndex:indexPath.row];
NSLog(#"Second=%#",self.array);
NSMutableArray * indexArry=[[NSMutableArray alloc]init];
for (NSInteger i=0; i< _optionImageArr.count; i++)
{
NSIndexPath * index =[NSIndexPath indexPathForRow:i inSection:0] ;
[indexArry addObject:index];
NSLog(#"%#",indexArry);
}
[collectionView reloadItemsAtIndexPaths:indexArry];
}
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