EXC_BAD_ACCESS when I scroll my view - objective-c

Question

I have two views: the first one is a UITableView in plain style (created programmatically); the second one is a UIScrollView that contains an image and a UITableView in grouped style (also created programmatically).
When I navigate from the firstView -> secondView everything works fine. However if I come back to the firstView and then I try to navigate firstView ->secondView for the second time, I get a EXC_BAD_ACCESS error.
UPDATE
This is the code of the UITableView delegate in the secondView:
-
(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
switch (section) {
case 0:
//header - breve descrizione
return 2;
break;
case 1: //mappa
//header - mappa statica (immagine) - footer (indirizzo)
return 3;
break;
case 2: //review
//header - prima review
return 2;
break;
default:
return 0;
break;
}
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
switch (indexPath.section) {
case 0:
switch (indexPath.row) {
case 0: //case titolo (header)
return HTABLE_DESCR_HEADER;
break;
case 1: //case corpo
return HTABLE_DESCR_BODY;
break;
default:
return 0;
break;
}
break;
case 1:
switch (indexPath.row) {
case 0: //case titolo (header)
return HTABLE_LOC_HEADER;
break;
case 1: //case corpo
return HTABLE_LOC_BODY;
break;
case 2: //case footer
return HTABLE_LOC_FOOTER;
break;
default:
return 0;
break;
}
break;
case 2:
switch (indexPath.row) {
case 0: //case titolo (header)
return HTABLE_REV_HEADER;
break;
case 1: //case corpo
return HTABLE_REV_BODY;
break;
default:
return 0;
break;
}
break;
default:
return 0;
break;
}
}
/*- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
return #"Travellers Guide";
}*/
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
int section = 2;
//se ci sono review
if ([[[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"list_review"] count] > 0) {
section++;
}
return section;
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [self getCellContentView:CellIdentifier];
}
cell.accessoryType = UITableViewCellAccessoryNone;
cell.selectionStyle = UITableViewCellSelectionStyleGray;
switch (indexPath.section) {
case 0: //descrizione
switch (indexPath.row) {
case 0: //header
if ([[[NSUserDefaults standardUserDefaults] objectForKey:#"language"] isEqualToString:#"it"]) {
cell.textLabel.text = #"Descrizione";
} else {
cell.textLabel.text = #"Description";
}
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.shadowColor = [UIColor whiteColor];
cell.textLabel.shadowOffset = CGSizeMake(1, 1);
cell.textLabel.highlightedTextColor = [UIColor blackColor];
cell.textLabel.font = [UIFont boldSystemFontOfSize:11.0];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"rigaDescrHeader.png"]];
break;
case 1: //descrizione
NSLog(#"Descr");
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"rigaRevBody.png"]];
cell.textLabel.text = [[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"description"];
cell.textLabel.font = [UIFont systemFontOfSize:10.0];
cell.textLabel.lineBreakMode = UILineBreakModeTailTruncation;
cell.textLabel.numberOfLines = 3;
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.shadowColor = [UIColor whiteColor];
cell.textLabel.shadowOffset =CGSizeMake(1, 1);
cell.textLabel.highlightedTextColor = [UIColor blackColor];
break;
default:
break;
}
break;
case 1: //mappa
//header - mappa statica (immagine) - footer (indirizzo)
switch (indexPath.row) {
case 0: //header
if ([[[NSUserDefaults standardUserDefaults] objectForKey:#"language"] isEqualToString:#"it"]) {
cell.textLabel.text = #"Posizione";
} else {
cell.textLabel.text = #"Location";
}
cell.textLabel.font = [UIFont boldSystemFontOfSize:11.0];
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.shadowColor = [UIColor whiteColor];
cell.textLabel.shadowOffset = CGSizeMake(1, 1);
cell.textLabel.highlightedTextColor = [UIColor blackColor];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"rigaLocHeader.png"]];
break;
case 1: //mappa
NSLog(#"Mappa");
CLLocationDegrees latitude = [[[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"latitude"] doubleValue];
CLLocationDegrees longitude = [[[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"longitude"] doubleValue];
CLLocation* poiLocation = [[[CLLocation alloc] initWithLatitude:latitude longitude:longitude] autorelease];
Annotation *ann = [Annotation annotationWithCoordinate:poiLocation.coordinate];
//mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, 320, HTABLE_LOC_BODY)];
[mapView setHidden:NO];
[mapView addAnnotation:ann];
MKCoordinateRegion region = {{0.0f, 0.0f}, {0.0f, 0.0f}};
region.center = poiLocation.coordinate;
region.span.longitudeDelta = 0.05f;
region.span.latitudeDelta = 0.05f;
[self.mapView setRegion:region animated:YES];
[self.mapView regionThatFits:region];
cell.backgroundView = mapView;
UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 302, 120)];
imgView.image = [UIImage imageNamed:#"ombraMappa.png"];
[cell.backgroundView addSubview:imgView];
[imgView release];
break;
case 2: //footer
cell.textLabel.text = [[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"locality"];
cell.textLabel.font =[UIFont systemFontOfSize:10.0];
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.shadowColor = [UIColor whiteColor];
cell.textLabel.shadowOffset = CGSizeMake(1, 1);
cell.textLabel.highlightedTextColor = [UIColor blackColor];
cell.detailTextLabel.text = [[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"address"];
cell.detailTextLabel.font = [UIFont boldSystemFontOfSize:9.0];
cell.detailTextLabel.textColor = [UIColor grayColor];
cell.detailTextLabel.backgroundColor = [UIColor clearColor];
cell.detailTextLabel.shadowColor = [UIColor whiteColor];
cell.detailTextLabel.shadowOffset = CGSizeMake(1, 1);
cell.detailTextLabel.highlightedTextColor = [UIColor blackColor];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"rigaLocFooter.png"]];
break;
default:
break;
}
break;
case 2: //review
//header - mappa statica (immagine) - footer (indirizzo)
switch (indexPath.row) {
case 0: //header
if ([[[NSUserDefaults standardUserDefaults] objectForKey:#"language"] isEqualToString:#"it"]) {
cell.textLabel.text = [NSString stringWithFormat:#"Recensioni (%d)",[[[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"list_review"] count]];
} else {
cell.textLabel.text = [NSString stringWithFormat:#"Review (%d)",[[[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"list_review"] count]];
}
cell.textLabel.font = [UIFont boldSystemFontOfSize:11.0];
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.shadowColor = [UIColor whiteColor];
cell.textLabel.shadowOffset = CGSizeMake(1, 1);
cell.textLabel.highlightedTextColor = [UIColor blackColor];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"rigaLocHeader.png"]];
break;
case 1: //review
cell.textLabel.text = [[[[[SingletonCardPOI sharedCardPOI] dicCard] objectForKey:#"list_review"] objectAtIndex:0] objectForKey:#"review"];
cell.textLabel.font =[UIFont systemFontOfSize:10.0];
cell.textLabel.lineBreakMode = UILineBreakModeTailTruncation;
cell.textLabel.numberOfLines = 3;
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.shadowColor = [UIColor whiteColor];
cell.textLabel.shadowOffset = CGSizeMake(1, 1);
cell.textLabel.highlightedTextColor = [UIColor blackColor];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"rigaRevBody.png"]];
break;
default:
break;
}
break;
default:
break;
}
return cell;
}
- (UITableViewCell *) getCellContentView:(NSString *)cellIdentifier {
UITableViewCell *cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];
return cell;
}

Answer 1

The EXC_BAD_ACCESS isn't caused by the progression of one view to the next. Rather, it will be properties of those views, or the creation and release - or not - of the view objects themselves that are to blame.
Your first step is to run the Analyzer. Then, if you've fixed all that and theres still a problem, start running the Leaks tool in Instruments.
For more details on resolving EXC_BAD_ACCESS issues, along with the excellent link on what causes these errors and step by step instructions for how to fix, have a look at answers to these questions:
finding reason for EXC_BAD_ACCESS - in Xcode4
Random EXC_BAD_ACCESS in a place that it cannot happen
In your case, I'd specifically look at how you are creating secondView, and what you do with firstView when you return to secondView.

Answer 2

I just spent a week tracking down a EXC_BAD_ACCESS problem in a large app that worked fine before converting it to ARC. I would get the EXC_BAD_ACCESS on the closing bracket of a "switch" construct. Yet NSZombieEnabled and the various Instrument settings would not detect anything for me.
What fixed it was putting curlies around the case's that made the difference. I did it for each of them, though perhaps it was critical for only some, i.e.
Before:
case ...:
stmt;
stmt;
break;
After:
case ...:{
stmt;
stmt;
}break;
This fixed the problem in two places within a large app for me. I know that I read something somewhere about ARC and switch/case (and maybe someone can add a link to it), but I don't understand the theory behind why this happened and why this fix worked. Perhaps someone could explain. (Later: after reading the following reference at openradar, it all makes sense --- there is something wrong in the "cleanup code" generated between case statements --- a bogus "release" is generated and that soon causes the EXC_BAD_ACCESS.)
I also discovered this, which might be related: http://openradar.appspot.com/11329693