Question

I’ve got a simple and yet difficult problem:

[self.scrollViewForKeyboard setContentOffset:CGPointMake(0, self.contentOffsetYBeforeEditing) animated:NO];
[self.scrollViewForKeyboard setContentOffset:CGPointMake(0, self.contentOffsetYBeforeEditing) animated:YES];

have a different effect at a certain point in my app: Not animating the content offset will scroll to the intended position, but changing the content offset with the animated flag set will make the UIScrollView scroll down too far. If I click/tap into the messed up UIScrollView, it will reset to the correct position set by the animation message above. If I animate the the scrolling by myself with an animation block, everything works fine.

The exact circumstances are way too difficult to explain here, cause the content I display is a bit complex, so my question is: Could it be possible, that the animation of the UIScrollView is somehow interfering with some other part of my app? What circumstances in genereal could cause such a behaviour?

Answer 1

One likely cause would be another animation happening at or near the same time affecting either the scroll view’s frame or contentSize.