My App has wrong behavior when I used UICollectionView API - scrollToItemAtIndexPath.( ios15 beta4)

Question

QiuZH OP

Created Sep ’21

Replies 3

Boosts 0

Participants 2

Model : iPhone 12 pro max

System : iOS 15 beta4

Desc : I set the collectionView to scroll to the back of the item, but it actually scrolls to the front. The problem is currently only in iPhone 12pro max.

NSInteger row = indexPath.item + 1; 
if (row > 0 && row < [self.dataSource collectionView:self numberOfItemsInSection:indexPath.section]) {   
     [UIView animateWithDuration:.3 animations:^{       
         [self scrollToItemAtIndexPath:[NSIndexPath    indexPathForRow:row inSection:indexPath.section]   atScrollPosition:UICollectionViewScrollPositionNone  animated:NO];      
      }];
 }

Answered by QiuZH in 687157022

It is correct in iOS 15 beta8

Boost

Answer 1

QiuZH OP

Sep ’21

NSInteger row = indexPath.item + 1; if (row > 0 && row < [self.dataSource collectionView:self numberOfItemsInSection:indexPath.section]) { [UIView animateWithDuration:.3 animations:^{ [self scrollToItemAtIndexPath:[NSIndexPath indexPathForRow:row inSection:indexPath.section] atScrollPosition:UICollectionViewScrollPositionNone animated:NO]; }]; }

0

Answer 2

Claude31 OP

Sep ’21

to the back of the item, but it actually scrolls to the front

Do you mean you want to scroll to next item and it scrolls to previous ?

Does the problem still occur if you remove animation ?

Could you try and change UICollectionViewScrollPositionNone to UICollectionViewScrollPositionCenteredVertically and tell what you get ?

Could you also log the value of indexPath and check it is correct one.

0

Answer 3

QiuZH OP

Sep ’21

Accepted Answer

It is correct in iOS 15 beta8

0