xcode CollectionViewController scrollToItemAtIndexPath not working

Question

I have created a CollectionView Control and filled it with images. Now I want to scroll to item at a particular index on start. I have tried out scrollToItemA

Answer 1

U can do this and on viewDidLoad method

just make call preformBatchUpdates

[self performBatchUpdates:^{
        if ([self.segmentedDelegate respondsToSelector:@selector(segmentedBar:selectedIndex:)]){
            [self.segmentedDelegate segmentedBar:self selectedIndex:_selectedPage];
        }
    } completion:^(BOOL finished) {
        if (finished){
            [self scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:_selectedPage inSection:0] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
        }

    }];

In my case my subclass CollectionView has a property selectedPage, and on a setter of this property i call

- (void)setSelectedPage:(NSInteger)selectedPage {
    _selectedPage = selectedPage;
    [self performBatchUpdates:^{
        if ([self.segmentedDelegate respondsToSelector:@selector(segmentedBar:selectedIndex:)]){
            [self.segmentedDelegate segmentedBar:self selectedIndex:_selectedPage];
        }
    } completion:^(BOOL finished) {
        if (finished){
            [self scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:_selectedPage inSection:0] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
        }

    }];
}

In view controller i calling this by code

- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationBar.segmentedPages.selectedPage = 1;
}