UIScrollView works as expected but scrollRectToVisible: does nothing
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by mahboudz
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Published on 2009-09-18T19:55:51Z
Indexed on
2010/03/17
5:51 UTC
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iphone
|uiscrollview
HI. I have used UIScrollView
before, and am using it now, and never had a problem. I'm now adding it to an old app, and while it works as expected (I can look at the contents, scroll around with my finger, all the bounds and sizes are setup right so there is no empty space in the content, etc.), I just can't get scrollToRectVisible
to work. I have even simplified the call so that it merely moves to the 0,0 position:
[scrollView scrollRectToVisible:CGRectMake(0, 0, 10, 10) animated:YES];
or move it to 0,200:
[scrollView scrollRectToVisible:CGRectMake(0, 200, 10, 10) animated:YES];
I even made a quick app to test this and I can get scrollRectToVisible
to work there as I expect. But in my old app, I can't seem to make it do anything.
I can make the scrollView scroll with setContentOffset:
, but that's not what I want.
This scrollView and its contents are defined in the nib by IB and used with an IBOutlet. The only code I am using in my app to handle the scrollView is
[scrollView setContentSize:CGSizeMake(scrollView.contentSize.width, imageView.frame.size.height)];
(I'm only interested in vertical scrolling not horizontal).
Has anyone run into a problem like this?
I have compared the scrollView attributes in both apps and they are identical.
ADDENDUM:
My scrollViews frame is: 0.000000 0.000000 480.000000 179.000000
My scrollViews contentSize is: 0.000000 324.000000
It still acts like the rect I want to scroll to is already visible and no scrolling is needed. Not sure if that is what is happening. This is just the darnest thing. Seems like such an easy thing to resolve...
ADDENDUM #2:
This is how I am making do without scrollRectToVisible
:
CGPoint point = myRect.origin;
if (![clefScrollView pointInside:point withEvent:nil]) {
point.x = 0;
if (point.y > clefScrollView.contentSize.height - clefScrollView.bounds.size.height)
point.y = clefScrollView.contentSize.height - clefScrollView.bounds.size.height;
[clefScrollView setContentOffset:point animated: YES];
}
Everything else about this scrollView works as expected, but scrollRectToVisible
. WHY?!? Any wild guesses?
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