Sensitivity/Scroll Speed of Uiscrollview with Paging

Sensitivity/Scroll speed of UIScrollView with paging

This is fairly straightforward, however you must implement the paging aspect yourself (which is fairly simple). You don't need gesture recognizers.

Swift

First, adjust your UIScrollView deceleration rate:

scrollView.decelerationRate = UIScrollViewDecelerationRateFast

Assume we have an array of content — let's call it yourPagesArray. In your UIScrollViewDelegate, implement the following method:

func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>)
{
    //This is the index of the "page" that we will be landing at
    let nearestIndex = Int(CGFloat(targetContentOffset.pointee.x) / scrollView.bounds.size.width + 0.5)

    //Just to make sure we don't scroll past your content
    let clampedIndex = max( min( nearestIndex, yourPagesArray.count - 1 ), 0 )

    //This is the actual x position in the scroll view
    var xOffset = CGFloat(clampedIndex) * scrollView.bounds.size.width

    //I've found that scroll views will "stick" unless this is done
    xOffset = xOffset == 0.0 ? 1.0 : xOffset

    //Tell the scroll view to land on our page
    targetContentOffset.pointee.x = xOffset
}

You will also need to implement the following delegate method, to handle the case where the user lifts their finger gently without causing any scroll deceleration:

(Update: you may not need to do this under the latest iOS SDK. It seems like the above delegate method is now called when there is zero velocity.)

func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool)
{
    if !decelerate
    {
        let currentIndex = floor(scrollView.contentOffset.x / scrollView.bounds.size.width)

        let offset = CGPoint(x: scrollView.bounds.size.width * currentIndex, y: 0)

        scrollView.setContentOffset(offset, animated: true)
    }
}

Objective-C

Setting your deceleration rate:

scrollView.decelerationRate = UIScrollViewDecelerationRateFast;

Then your scroll view delegate implementation:

- (void) scrollViewWillEndDragging:(UIScrollView *)scroll withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
{
    //This is the index of the "page" that we will be landing at
    NSUInteger nearestIndex = (NSUInteger)(targetContentOffset->x / scrollView.bounds.size.width + 0.5f);   

    //Just to make sure we don't scroll past your content
    nearestIndex = MAX( MIN( nearestIndex, yourPagesArray.count - 1 ), 0 );

    //This is the actual x position in the scroll view
    CGFloat xOffset = nearestIndex * scrollView.bounds.size.width;

    //I've found that scroll views will "stick" unless this is done
    xOffset = xOffset==0?1:xOffset;

    //Tell the scroll view to land on our page
    *targetContentOffset = CGPointMake(xOffset, targetContentOffset->y);
}

- (void) scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    if( !decelerate )
    {
        NSUInteger currentIndex = (NSUInteger)(scrollView.contentOffset.x / scrollView.bounds.size.width);

        [scrollView setContentOffset:CGPointMake(scrollView.bounds.size.width * currentIndex, 0) animated:YES];
    }
}

Adjusting UICollectionView scroll speed/sensitivity

UICollectionView is a subclass of UIScrollView, so you can adjust the decelerationRate in your collection view controller's viewDidLoad, like so:

Objective-C:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.collectionView.decelerationRate = UIScrollViewDecelerationRateFast;
};

Swift:

override func viewDidLoad() {
    super.viewDidLoad()

    self.collectionView.decelerationRate = UIScrollViewDecelerationRateFast
}

Swift -prevent fast scrolling when collectionView.isPagingEnabled = true

this answer worked:

func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {

    scrollView.isUserInteractionEnabled = false
}

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {

    scrollView.isUserInteractionEnabled = true
}

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