iOS: Not full frame of UICollectionViewCell is tappable/clickable - ios

Question

I created a UIView with a UICollectionView, and that UIView is added on a UIViewController. UIViewController using the delegate (photoDidTapped) of that UIView to determine is something was clicked/tapped. First row, is okay, means whole cell area is tappable. Second row, horizontal half of that is clickable. 3rd row, almost 10% horizontal of the cell is clickable and so on.
Code:
- (UICollectionView *)collectionView
{
if (!_collectionView) {
UICollectionViewFlowLayout *flowLayout=[[UICollectionViewFlowLayout alloc] init];
flowLayout.itemSize = CGSizeMake(THUMB_DIMENSION, THUMB_DIMENSION);
[flowLayout setMinimumInteritemSpacing:0.0f];
[flowLayout setMinimumLineSpacing:PHOTO_MARGIN];
_collectionView = [[UICollectionView alloc] initWithFrame:self.frame collectionViewLayout:flowLayout];
_collectionView.frame = CGRectMake(0, 0, SCREEN_WIDTH, self.frame.size.height);
_collectionView.backgroundColor = [UIColor clearColor];
_collectionView.delegate = self;
_collectionView.dataSource = self;
_collectionView.allowsSelection = YES;
_collectionView.alwaysBounceVertical = YES;
_collectionView.scrollEnabled = NO;
[_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:#"Cell"];
}
return _collectionView;
}
- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section {
return (_photos.count > 9 ? 9 : _photos.count);
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath; {
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"Cell" forIndexPath:indexPath];
UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, cell.frame.size.width, cell.frame.size.height)];
imgView.clipsToBounds = YES;
imgView.backgroundColor = RGB(250, 250, 250);
if (_photos.count) {
PhotoDM *photo = [_photos objectAtIndex:indexPath.row];
[imgView setImageWithURL:[NSURL URLWithString:photo.largeLink]
placeholderImage:[UIImage imageNamed:#"placeholder"]];
}
[cell addSubview:imgView];
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"tapped: %ld", (long)indexPath.row);
if([delegate respondsToSelector:#selector(photoDidTapped:)])
[delegate performSelector:#selector(photoDidTapped:) withObject:[[NSNumber alloc] initWithInteger:indexPath.row] ];
}

Answer 1

Your code contains 2 problems.
1. If you create a subview, you should use self.bounds.
2. The view can be resized, after UICollectionView has been added. It means that you should configure autoresizingMask or NSLayoutConstrans. (UICollectionView can be out of view's bounds).
To debug this problem, you can create different background colors for the view, the collectionView, the viewController's view.