Deactivate UIScrollView decelerating

Question

Is there a way to deactivate the decelerating of a UIScrollView?

I want to allow the user to scroll the canvas, but I don't want that the canvas continues scrolling after the user lifted the finger.

Answer 1

This can be done by utilizing the UIScrollView delegate method scrollViewWillBeginDecelerating to automatically set the content offset to the current screen position.

To implement:

1. Assign a delegate to your UIScrollView object if you have not already done so.

2. In your delegate's .m implementation file, add the following lines of code:

   -(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{       [scrollView setContentOffset:scrollView.contentOffset animated:YES];    } 

Voila! No more auto-scroll.

Answer 2

For iOS 5.0 or later, there is a better method than calling setContentOffset:animated:.

Implement delegate method scrollViewWillEndDragging:withVelocity:targetContentOffset: in your .m file:

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView                      withVelocity:(CGPoint)velocity               targetContentOffset:(inout CGPoint *)targetContentOffset {     targetContentOffset.pointee = scrollView.contentOffset; } 

Assigning the current offset to targetContentOffset stops the UIScrollView from auto-scrolling.