UICollectionView not adapting to iPad screen during rotation - uicollectionview

Question

#pragma mark Rotation handling methods
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:
(NSTimeInterval)duration {
NSLog(#"IS ROTATING");
// Fade the collectionView out
[self.collectionView setAlpha:0.0f];
// Suppress the layout errors by invalidating the layout
[self.collectionView.collectionViewLayout invalidateLayout];
// Calculate the index of the item that the collectionView is currently displaying
CGPoint currentOffset = [self.collectionView contentOffset];
self.currentIndex = currentOffset.x / self.collectionView.frame.size.width;
}
- (void)viewWillLayoutSubviews;
{
[super viewWillLayoutSubviews];
UICollectionViewFlowLayout *flowLayout = (id)self.collectionView.collectionViewLayout;
if (UIDeviceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation])) {
flowLayout.itemSize = CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height);
} else {
flowLayout.itemSize = CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height);
}
[flowLayout invalidateLayout]; //force the elements to get laid out again with the new size
}
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
// Force realignment of cell being displayed
CGSize currentSize = self.view.bounds.size;
float offset = self.currentIndex * currentSize.width;
[self.collectionView setContentOffset:CGPointMake(offset, 0)];
NSLog(#"CURRENT bounds: %f",self.view.bounds.size.width);
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:self.currentIndex inSection:0];
[self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];
// Fade the collectionView back in
[UIView animateWithDuration:0.125f animations:^{
[self.collectionView setAlpha:1.0f];
}];
}
This is the code. I just want the image to maintain full screen and the collection view is conforming to portrait. I can see that the cells are trying to adjust, but the collection view itself is not resizing. Any suggestions/fixes?

Answer 1

Where do you set the new frame for the collectionView? Either you should set it in willAnimateRotationToInterfaceOrientation: duration: or didRotateFromInterfaceOrientation: or if its equal to the size of the superview, then set the resizing mask to flexible width or height.
_collectionView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
In viewWillLayoutSubviews you are setting the itemSize in landscape and portrait for the same, is it intended?