What's happening
Currently I have an application that uses two UICollectionViews
inside a UITableView
. This way I create a Pulse News look like application. My problem with this is that sometimes the 6th and 11th row disappears completely, leaving a blank space where it should be the cell. I wouldn't actually mind, if all the cells were like this (and this way I could assume that I wasn't doing things correctly), but the thing is, is just happening with those specific ones.
My theory
The 6th and 11th rows are the ones that appears when I start scrolling, so by default I am able to see 5 cells, and when I do the first horizontal scrolling the 6th comes up (blank space sometimes).
What I have
The only thing I am doing at the moment is this:
[self.collectionView registerNib:[UINib nibWithNibName:CELL_NIB_NAME bundle:nil] forCellWithReuseIdentifier:CELL_IDENTIFIER];
On the viewDidLoad
. And on the creation of the cell:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MyCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:CELL_IDENTIFIER forIndexPath:indexPath];
NSMutableDictionary *dictionary = [self.DataSource objectAtIndex:[indexPath row]];
[cell buildViewWithDictionary:dictionary withReferenceParent:self.referenceViewController];
return cell;
}
So on my understating nothing fancy going on here. I though there was something wrong on the data source (a dummy JSON file), but sometimes it works ok and the cell shows, so I guess from that part is ok.
So my "question": Does anyone knows what's going on? I don't really like to say that it's a bug from iOS, but I can't think of anything else.
Edit 1.0
The amazing part is that this method
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath;
Is going from indexPath
[0,4] to [0,6] without calculating the [0,5]. First time I actually see this happening in iOS.
Edit 2.0
I have switched the way I am creating the cells, and instead of dequeuing I am using the old way:
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:CELL_NIB_NAME owner:self options:nil];
MyCell *cell = (MyCell *)[nib objectAtIndex:0];
Still the same sad result.
So, what did work?
1) Subclass UICollectionViewFlowLayout
.
2) Set the flowLayout of my UICollectionView
to my new subclass.
3) On the init method of the UICollectionViewFlowLayout
subclass, set the orientation you want:
self.scrollDirection = UICollectionViewScrollDirectionHorizontal;
In my case it is Horizontal.
4) The important part:
-(BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds
{
return YES;
}
At this moment, I should theorise a bit, but honestly I don't have a clue.