UICollectionView with FlowLayout not scrolling when setting section insets

Question

I am using a UICollectionView programmatically.

I\'ve set its frame as follows:

UICollectionView *collectionView = [[UICollectionView alloc] initWithFram         


        

Answer 1

In answering some of your other questions about UICollectionView, I created this demo project, and it scrolls just fine, so I don't know what problem you're having. The only thing I needed to do to make the last row wholly visible was to increase the size of the bottom inset to 90. I also added a completion method to the performBatchUpdates:completion: to automatically scroll so that the last added item is visible (notice that I add some extra items by using performSelector;withObject:afterDelay:). My images are 48x48, and I just set my collection view to the bounds of my controller's view. Here is the code so you can compare it to what you have:

@interface ViewController ()  {
NSMutableArray *newData;
}
 @property (nonatomic, retain) UICollectionView *collectionView;
 @property (nonatomic, retain) NSMutableArray *results;
 @end

@implementation ViewController

- (void)viewDidLoad {
    self.results = [NSMutableArray array];
    int i = 11;
    while (i<91) {
        UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"New_PICT00%d.jpg",i]];
        [self.results addObject:image];
        i++;
    }

    UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
    //flowLayout.scrollDirection =  UICollectionViewScrollDirectionHorizontal;

    self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:flowLayout];
    self.collectionView.dataSource = self;
    self.collectionView.delegate = self;
    self.view.backgroundColor = [UIColor blackColor];
    [self.view addSubview:self.collectionView];
    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"Cell"];
    //[self.collectionView registerClass:[RDCell class] forCellWithReuseIdentifier:@"myCell"];
    [self.collectionView reloadData];

    [self performSelector:@selector(addNewImages:) withObject:nil afterDelay:3];
}

-(void)addNewImages:(id)sender {
    newData = [NSMutableArray array];
    int i = 102;
    while (i<111) {
        UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"New_PICT0%d.jpg",i]];
        [newData addObject:image];
        i++;
    }
    [self addNewCells];
}

-(void)addNewCells {
    NSMutableArray *arrayWithIndexPaths = [NSMutableArray array];
    [self.collectionView performBatchUpdates:^{
        int resultsSize = [self.results count];
        [self.results addObjectsFromArray:newData];
        for (int i = resultsSize; i < resultsSize + newData.count; i++)
            [arrayWithIndexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
        [self.collectionView insertItemsAtIndexPaths:arrayWithIndexPaths];
    }
    completion: ^(BOOL finished){
        [self.collectionView scrollToItemAtIndexPath:arrayWithIndexPaths.lastObject atScrollPosition:UICollectionViewScrollPositionCenteredVertically animated:YES];
    }];
}


- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section {
    return [self.results count];
}

- (NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionView {
    return 1;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
    //cell.iv.image = [self.results objectAtIndex:indexPath.row];
    cell.backgroundColor = [UIColor colorWithPatternImage:[self.results objectAtIndex:indexPath.row]];
    return cell;
}


- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    UIImage *image = [self.results objectAtIndex:indexPath.row];
    return CGSizeMake(image.size.width, image.size.height);
}

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    return UIEdgeInsetsMake(10, 10, 90, 10);
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"Selected Image is Item %d",indexPath.row);
}