从NSZombieEnabled获取没有任何有用消息的EXC_BAD_ACCESS

Question

我是iphone开发的新手,我一直在努力解决几天前发生的EXC_BAD_ACCESS错误.我基本上独立地使用斯坦福iphone类,我试图将一个NSManagedObjects数组传递给一个应该显示它们的TableViewController.应用程序在模拟器中启动并在tableView中显示数据,但它会立即出现EXC_BAD_ACCESS错误.

我按照这里和其他地方的说明如何使用NSZombieEnabled来识别过早释放的对象,但即使使用NSZombieEnabled也没有任何有用的消息.我的猜测是它必须是由于试图访问未通过发布/自动释放释放的未分配内存而导致的.否则它会被视为僵尸对象,就像我能够修复的其他错误一样.我不是专家,但如果我要声明一个对象并在没有实例化的情况下发送消息,那么这意味着会发生这样的事情吗？我查看了我的代码,看看我是否有类似的东西,我空了.

我在调试器中有堆栈跟踪,但我不知道如何使用它.我有点沮丧,因为我不能在代码中使用断点来进一步缩小问题,因为它似乎发生在应用程序加载完成后.如果没有可能的用户交互,我认为该应用程序将保持闲置状态.它是否在负载的尾端失败,我不能轻易看到它或者在完成加载后突然在后台做东西.我非常感谢有关如何阅读堆栈跟踪的任何提示.

我在下面键入了我的堆栈跟踪(无法弄清楚如何从调试器中复制它)

0 objc_msgSend
1 ??
2 -[NSManagedObject dealloc]
3 -[_PFManagedObjectReferenceQueue _processReferenceQue:]
4 _performRunLoopAction
5 ___CFRunLoopDoObservers
6 CFRunLoopRunSpecific
7 CFRunLoopRunInMode
8 GSEventRunModal
9 GSEventRun
10 UIApplicationMain
11 main

我的程序中的两个主要类是顶级委托类和它调用的ViewTableController.

` - (void)applicationDidFinishLaunching:(UIApplication*)application {

self.tabBarController = [[[UITabBarController alloc] init] autorelease];        

UINavigationController *contactsNavigationController = [[self createContactsNavigationController] retain];

//UINavigationController *recentsNavigationController = [[self createRecentsNavigationController:photos] retain];

tabBarController.viewControllers = [[NSArray alloc] initWithObjects: contactsNavigationController, nil];

[contactsNavigationController release];
//[recentsNavigationController release];

[window addSubview:tabBarController.view];
    [window makeKeyAndVisible];

}

- (UINavigationController*)createContactsNavigationController {

UINavigationController *contactsNavigationController = [[UINavigationController alloc] init];

UITabBarItem *contactsTabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem: UITabBarSystemItemContacts tag:0];
contactsNavigationController.tabBarItem=contactsTabBarItem ;
[contactsTabBarItem  release];


PersonListViewController *personListViewController = [[PersonListViewController alloc] initWithStyle:UITableViewStylePlain];    

NSManagedObjectContext *context = [self managedObjectContext];
personListViewController.managedObjectContext=context;

personListViewController.contacts = [self createContacts];
[context release];

personListViewController.title=@"Contacts";

[contactsNavigationController pushViewController:personListViewController animated:false];
return [contactsNavigationController autorelease];

}`

` - (NSArray*)readContacts {

NSString *path = [[NSBundle mainBundle] bundlePath];

NSString *filePath = [path stringByAppendingPathComponent:@"FakeData.plist"];
NSArray *plist = [[NSMutableArray arrayWithContentsOfFile:filePath] retain];

return [plist autorelease];
}

- (NSMutableArray *)createContacts {

NSArray * plist = [[self readContacts] retain
NSMutableArray *contactNames = [[NSMutableArray alloc] init];
NSMutableArray *contacts = [[NSMutableArray alloc] init];
for (NSDictionary *photo in plist) {
    NSString *contactName = [photo objectForKey:@"user"];
    Person *contact = nil;
    if (![contactNames containsObject:contactName]) {
        contact  = (Person *)[NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:managedObjectContext];
        contact.name =contactName;
        NSError *error;
        if (![managedObjectContext save:&error]) {
            NSLog(@"SHIT the save person FAILED!!!  %@",error);
        }

        [contacts addObject:contact];
        [contactNames addObject:contactName];



    } else {
        contact = [contacts objectAtIndex:[contactNames indexOfObject:contactName]];
    }

    [contactName release];

    Photo *image = (Photo *)[NSEntityDescription insertNewObjectForEntityForName:@"Photo" inManagedObjectContext:managedObjectContext];

    image.imageFile = [photo objectForKey:@"path"];
    image.imageName = [photo objectForKey:@"name"];
    image.owner = contact;

    contact.photos = [NSSet setWithObjects:image,nil];


     NSError *error;
     if (![managedObjectContext save:&error]) {
         NSLog(@"SHIT the save photoFAILED!!!  %@",error);
     }

    [image release];
    [contact release];
}

[plist release];

return [contacts autorelease];
}

如果我的代码太糟糕,无法阅读,我深表歉意.

谢谢你的帮助.

Answer 1

这是你的问题:

NSString *contactName = [photo objectForKey:@"user"];
... a bunch of lines later
[contactName release];

objectForKey:返回一个autoreleased对象,你不应该释放它.

同样,insertNewObjectForEntityForName:inManagedObjectContext:managedObjectContext返回一个autoreleased对象,所以删除[image release]和[contact release]