Question: Scroll child scrollview only when parent scroll view reaches end

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Scroll child scrollview only when parent scroll view reaches end

Answers 2
Added at 2017-01-04 11:01
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I have a parent UIScrollView and a UICollectionView inside that UIScrollView. I want that UICollectionView scroll begins only when the parent UIScrollView reaches end of its scrolling. Can any one please help me for the same.

Answers
nr: #1 dodano: 2017-01-04 11:01

In viewDidLoad, Disable Collectionview scroll.

self.collectionView.scrollEnabled = NO;

Now, Use Delegate of scrollview to detect bottom of the scroll view and than enable CollectionView scroll.

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    float bottomEdge = scrollView.contentOffset.y + scrollView.frame.size.height;
    if (bottomEdge >= scrollView.contentSize.height) {
       self.collectionView.scrollEnabled = YES;
    }
}

Hope it will work.

nr: #2 dodano: 2017-01-04 11:01

Initially set the child scrollView yourScrollView.scrollEnabled = NO; also add tags to your scrollViews. 1 for parent and 2 for child preferably.

Get to know if you are at the bottom of the ScrollView using this code

-(void)scrollViewDidScroll: (UIScrollView*)scrollView
{
    if(scrollView.tag==1)
    {
    float scrollViewHeight = scrollView.frame.size.height;
    float scrollContentSizeHeight = scrollView.contentSize.height;
    float scrollOffset = scrollView.contentOffset.y;

    if (scrollOffset == 0)
    {
        // then we are at the top
    }
    else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)
    {
        //Handle Code to activate the child scrollView.
        // then we are at the end
    }
    }
}

Hope this helps. Happy Coding.

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