using completion with animateWithDuration causes exc_bad_access

Question

I am trying to animate 2 UIButtons in a UITableViewCell called addToPlaylist and removeFromPlayList (they animate off to the right after being swiped on) and am using a block as follows

[UIView animateWithDuration:0.25 animations:^{

    self.addToPlaylist.center      = CGPointMake(contentsSize.width + (buttonSize.width / 2), (buttonSize.height / 2));
    self.removeFromPlaylist.center = CGPointMake(contentsSize.width + (buttonSize.width / 2), (buttonSize.height / 2));
    myImage.alpha = 1.0;

}
 completion:^ (BOOL finished) 
 {
     if (finished) {
         // Revert image view to original.
         NSLog(@"Is completed");
         self.addToPlaylist.hidden       = YES;
         self.removeFromPlaylist.hidden  = YES;
         self.hasSwipeOpen               = NO;
     }
 }];

on completion I want to hide the buttons to attempt to lessen redraw on scroll etc.

This code sits within '-(void) swipeOff' which is called in the UITableViewControllers method scrollViewWillBeginDragging like so:

- (void)scrollViewWillBeginDragging:(UIScrollView *) scrollView
{
   for (MediaCellView* cell in [self.tableView visibleCells]) {
        if (cell.hasSwipeOpen) {
           [cell swipeOff];
        }
    }
}

The problem is the completion code, if I remove it or set it to nil all is good, if I include it I get an EXC_BAD_ACCESS. even if I include it with any or all of the lines within the if(finished) commented out

Am I using this in the wrong way, any help much appreciated.

Thanks

If you leave out the assignments and keep the NSLog, does the code work without crash? Does it always crash or just when the tableview scrolls? — Nick Weaver, May 11 '11 at 06:40
Hi Nick, it will still crash with just the NSLog in there, and it is only when the tableView scrolls — craigk, May 11 '11 at 10:14

score 20 · Accepted Answer · edited May 23 '17 at 11:45

20

I had the same problem with animations. I've solved it by removing -weak_library /usr/lib/libSystem.B.dylib from Other Linker flags.

Also, according to this answer, if you need this flag, you may replace it with -weak-lSystem.

edited May 23 '17 at 11:45

Community

1
1

answered Jun 10 '11 at 06:57

ivanzoid

5,952
2
34
43

thanks mate, I had given up on that one. I had to use the -weak-lSystem but it got rid of the crash/error. +1 for the links – craigk Jun 13 '11 at 23:48

score 0 · Answer 2 · edited Apr 11 '19 at 03:52

0

Check if you are not calling a UIView (collectionView, Mapview, etc) from inside the UIView block, meaning, it would be a call outside the main thread. If you are, try this:

DispatchQueue.main.async {
self.mapBoxView.setZoomLevel(self.FLYOVERZOOMLEVEL, animated: true
)}

edited Apr 11 '19 at 03:52

xskxzr

12,442
12
37
77

answered Apr 11 '19 at 03:33

TDesign

569
4
8

using completion with animateWithDuration causes exc_bad_access

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