Artifact after changing uicollectionviewlayout

Question

I'm switching between layouts in a uicollectionview using this code

-(void)setHorizontalLayout:(BOOL)layout
{
    if (layout == YES)
    {

        [self.collectionView performBatchUpdates:^{
            [self.collectionView setCollectionViewLayout:self.horizontalPagingLayout animated:NO];
            [self.collectionView setPagingEnabled:YES];
            self.galleryInHorizontalScrollMode = YES;
        } completion:^(BOOL finished) {
            [self.collectionView reloadData];
        }];
    }
    else {


        [self.collectionView performBatchUpdates:^{

            [self.collectionView setCollectionViewLayout:self.galleryLayout animated:NO];
            self.galleryInHorizontalScrollMode = NO;
            [self.collectionView setPagingEnabled:NO];
        } completion:^(BOOL finished) {
            [self.collectionView reloadData];
        }];
    }

    return;
}

but after I change from one layout to the other I am getting the [0,0] indexpathed cell set as the uicollectionview's background. I suspect something with the layer is messed up. And looking over the call stack all looks fine. I can't see any calls to animations that may be messing with the layer.

Any way to invalidate this? what could cause it?

What does "cell set as the uicollectionview's background" mean? Literal interpretation: the collection view's `backgroundView` property is a cell instance. Likely interpretation: the cell's frame is equal to the collection view's bounds. — Timothy Moose, Aug 25 '13 at 15:58

score 0 · Answer 1 · answered Aug 26 '13 at 08:50

I'm not sure on why this behavior happens but when I invalidated the layout before changing the layout all works as expected:

[self.collectionView performBatchUpdates:^{
            ***[self.collectionView.collectionViewLayout invalidateLayout];***
            [self.collectionView setCollectionViewLayout:self.horizontalPagingLayout animated:NO];
        } completion:^(BOOL finished) {
            [self.collectionView reloadData];
        }];

Artifact after changing uicollectionviewlayout

1 Answers1