how to scroll collection view automatically between time intervel to display images get from backend services?

Asked Jun 21 '17 at 04:54

Active Jun 22 '17 at 09:42

Viewed 27 times

I am developing an application based on getting images from backend service and displaying on collection view which have to scroll automatically in horizontal direction.

-(void)scrollAutomatically:(NSIndexPath *)pathRef {

    [_collectionView scrollToItemAtIndexPath:pathRef atScrollPosition:UICollectionViewScrollPositionRight animated:YES];

if (row ==adImgsArr.count-1) {
    _pageControl.currentPage = row;

    row = 0;
}
else
{
    _pageControl.currentPage = row;

    row = row + 1; 
}
pathRef =  [NSIndexPath indexPathForRow:row inSection:section];
[self performSelector:@selector(scrollAutomatically:) withObject:pathRef afterDelay:5.0];

}

I am using the following code, but sometimes its working properly and sometimes it getting crash.

what is modification i need to do here ?

edited Jun 22 '17 at 09:42

asked Jun 21 '17 at 04:54

Charishma Vasamsetti

Add exception here and you can add Timer also which is correct way to call methods repeatedly. – Chanchal Warde Jun 21 '17 at 05:32
can you please give me example – Charishma Vasamsetti Jun 21 '17 at 06:17
i'm getting crash at this particular line of code [_collectionView scrollToItemAtIndexPath:pathRef atScrollPosition:UICollectionViewScrollPositionRight animated:YES]; – Charishma Vasamsetti Jun 21 '17 at 06:27
Print visible cell of collection view and then print row index where you want to scroll. You'll get your answer. – Chanchal Warde Jun 21 '17 at 08:27
thank you very much...it was very helpful... – Charishma Vasamsetti Jun 21 '17 at 10:58
Always try to backtrack and follow po in console or print statements. Half of the time it'll solve your problem. First reload your desired index path so that indexpath will become visible and then scroll to that position. You were moving to index which was not loaded. – Chanchal Warde Jun 21 '17 at 11:47

how to scroll collection view automatically between time intervel to display images get from backend services?

0 Answers0