EXC_BAD_ACCESS crash when switching back and forth between views - ios

Question

I'm getting a EXC_BAD_ACCESS crash when switching back and forth between views. I'm having a problem finding the cause of this crash. In the simulator it always goes back to the main.m file and reports the crash in it.
But on my device the EXC_BAD_ACCESS show up on my custom UITableViewCell when I release it in the dealloc method. If I enable NSZombieEnabled my app doesn't crash at all.
Here is the .h file
#import <UIKit/UIKit.h>
#define kWinsAmountTagValue 2 // how many wins you have
#define kWinningsAmountTagValue 3 // how much money you won
#interface MyStatsViewController : UIViewController
<UITableViewDelegate, UITableViewDataSource,
UINavigationBarDelegate, UINavigationControllerDelegate>{
NSArray *list;
UITableView *theTable;
UITableViewCell *theCell;
}
#property (nonatomic, retain) NSArray *list;
#property (nonatomic, retain) IBOutlet UITableView *theTable;
#property (nonatomic, retain) IBOutlet UITableViewCell *theCell;
// dealloc and cleanup
-(void) dealloc;
// misc methods
-(void)loadData;
// demo data
-(NSArray *)tableData;
#end
Here is my .m file
#import "MyStatsViewController.h"
#implementation MyStatsViewController
#synthesize list;
#synthesize theTable;
#synthesize theCell;
#pragma mark - dealloc and cleanup
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
NSLog(#"Memory Warning");
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
self.list = nil;
self.theTable = nil;
self.theCell = nil;
}
- (void)dealloc
{
[super dealloc];
[list release];
[theTable release];
[theCell release];
}
#pragma mark - misc methods
-(void) loadData
{
self.list = [self tableData];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
}
-(void)viewWillAppear:(BOOL)animated
{
[self loadData];
[theTable reloadData];
}
#pragma mark - Table Data Source Methods
-(NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section
{
return [list count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier =#"MyStatsCustomCellIdentifer";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: CellIdentifier];
NSUInteger row = [indexPath row];
if (cell == nil) {
if (row == [list count] -1) {
cell = [[[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier] autorelease];
} else {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"MyStatsCustomCell"
owner:self
options:nil];
if ([nib count] > 0) {
cell = self.theCell;
} else {
NSLog(#"failed to load MyStatsCustomCell");
}
}
}
// Add custom stuff here for rows
//cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
if (row == [list count] -1) {
cell.textLabel.text = [list objectAtIndex:row];
} else {
UILabel *prizeLevel = (UILabel *)[cell viewWithTag:kPrizeLevelTagValue];
prizeLevel.text = [[list objectAtIndex:row] objectForKey:#"prizeLevel"];
UILabel *winsAmount = (UILabel *)[cell viewWithTag:kWinsAmountTagValue];
winsAmount.text = [[list objectAtIndex:row] objectForKey:#"winsAmount"];
UILabel *winningsAmount = (UILabel *)[cell viewWithTag:kWinningsAmountTagValue];
winningsAmount.text = [[list objectAtIndex:row] objectForKey:#"winningsAmount"];
}
//NSLog(#"theCell Retain: %i",[theCell retainCount]);
return cell;
}
#pragma mark - Table View Delegate Methods
-(void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
#pragma mark - demo data
-(NSArray *)tableData
{
NSArray *prizeLevels = [[NSArray alloc] initWithObjects:
#"6-of-6", #"5-of-6", #"4-of-6",#"3-of-6", nil];
NSArray *winsAmount = [[NSArray alloc] initWithObjects:
#"0", #"0", #"2", #"100", nil];
NSArray *winngingsAmount = [[NSArray alloc] initWithObjects:
#"$0",#"$0", #"$45.50",#"$125.00", nil];
NSMutableArray *myGames = [[[NSMutableArray alloc] init] autorelease];
for (int i = 0; i < [prizeLevels count]; i++) {
NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
[dict setObject:[prizeLevels objectAtIndex:i] forKey:#"prizeLevel"];
[dict setObject:[winsAmount objectAtIndex:i] forKey:#"winsAmount"];
[dict setObject:[winngingsAmount objectAtIndex:i] forKey:#"winningsAmount"];
[myGames addObject:dict];
[dict release];
}
[prizeLevels release];
[winsAmount release];
[winngingsAmount release];
[myGames addObject:#"Spent: $1250.00"];
return myGames;
}
#end
Any help would be appreciated.

Answer 1

It is a good practice to clean up class's own variables before calling the super's destructor. A lot more details can be found here: Why do I have to call super -dealloc last, and not first?.