UICollectionView滚动到特定部分

Question

Using Objective C and Xcode I have created a UICollectionView with 10 sections and all works fine. Is there anyway to set the section to which is viewed when first shown? By default it shows sections 0-9, but I want it to start at section 5.

Answer 1

You can call scrollToItemAtIndexPath:atScrollPosition:animated: in your viewDidAppear: method.

You can hold a reference to the cell you want to scroll to, then use indexPathForCell: to get the index path.

The following are the scroll positions you can choose from

UICollectionViewScrollPositionNone
UICollectionViewScrollPositionTop
UICollectionViewScrollPositionCenteredVertically
UICollectionViewScrollPositionBottom
UICollectionViewScrollPositionLeft
UICollectionViewScrollPositionCenteredHorizontally
UICollectionViewScrollPositionRight

Answer 2

In case you know where you want to scroll to in terms of an integer row and section, you can use those integers in the

NSIndexPath indexPathForItem:inSection:

method to create an NSIndexPath instead of keeping a reference to a cell and then calling indexPathForCell:. Also, you can move this code to the viewWillAppear: method if you want the scrolling to happen before the view is displayed.