iphone之核心数据 NSObjectInaccessibleException NSManagedObject 已失效
jackei
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2025-06-02 22:19:02
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我有一些代码可以将类(class)下载为 JSON、解析它们并将它们放入核心数据中。然后将它们显示在 UITableView 中。目前，当用户有很多类(class)时，连接有时会超时。因此，我试图在类(class)进入时解析类(class)(使用 SBJson)，并一次将它们添加到 tableview 中。
两者的代码基本相同，但是新的代码导致tableView的东西启动时崩溃，并报错
"Terminating app due to uncaught exception
'NSObjectInaccessibleException', reason: 'The NSManagedObject with ID:0x5ad0570 <x-coredata://A21AC71F-175B-423D-BF7D-C67BEE094460/Lessons/p18> has been invalidated.'"
我想知道这两个可能导致此错误的代码 list 之间的区别是什么。原始代码在循环中创建每个核心数据对象，但新代码在下载每个核心数据对象时创建它。 listViewArray 是用于填充 UITableView 的数组。
我正在使用 SBJsonStreamParser 和 SBJsonStreamParserAdapter 来解析 Json。
我确实有一个有效的实现(未显示)，它基本上每次接收到一个新对象时都会调用下面的原始代码(每次都通过接收到的对象的完整循环运行)。不过，我想知道是什么导致了错误，而不仅仅是让某些东西正常工作。
这是原始的非流式代码，在 connectionDidFinishLoading 中调用:
NSMutableArray *tempListArray = [[NSMutableArray alloc] initWithArray:jsonStreamedData];
if (listViewArray)
[listViewArray release];
listViewArray = [[NSMutableArray alloc] init];
if(![tempListArray count]){
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Message" message:@"No active lessons " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
[alertView show];
[alertView release];
}
else {
MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
NSError *error = nil;
[appDelegate.managedObjectContext reset];
NSManagedObjectContext *managedObjectContext = appDelegate.managedObjectContext;
for (int i = 0; i < [tempListArray count]; i++) {
NSFetchRequest *checkRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *lessonEntity = [NSEntityDescription entityForName:@"Lessons" inManagedObjectContext:managedObjectContext];
[checkRequest setEntity:lessonEntity];
NSPredicate *langPredicate = [NSPredicate predicateWithFormat:@"(language = %@)", appDelegate.currentLanguage];
NSPredicate *userPredicate = [NSPredicate predicateWithFormat:@"(username = %@)", appDelegate.userName];
NSPredicate *idPredicate = [NSPredicate predicateWithFormat:@"(content_Id = %@)", [[tempListArray objectAtIndex:i] valueForKey:@"id"]];
[checkRequest setPredicate:[NSCompoundPredicate andPredicateWithSubpredicates:[NSArray arrayWithObjects:langPredicate, userPredicate, idPredicate, nil]]];
NSArray *checkResults = [managedObjectContext executeFetchRequest:checkRequest error:&error];
[checkRequest release];
NSMutableDictionary *tempDict = [[NSMutableDictionary alloc] init];
if ([checkResults count]) {
Lessons *lessonObj = [checkResults objectAtIndex:0];
lessonObj.cards_count = [[tempListArray objectAtIndex:i] valueForKey:@"cards_count"];
lessonObj.mTitle = [[tempListArray objectAtIndex:i] valueForKey:@"title"];
lessonObj.sound_Url = [[tempListArray objectAtIndex:i] valueForKey:@"audio_url"];
lessonObj.mId = [NSNumber numberWithInt:i];
[tempDict setValue:lessonObj forKey:@"lesson"];
[tempDict setValue: [[tempListArray objectAtIndex:i] objectForKey:@"image_url"] forKey:@"image_url"];
[listViewArray addObject:tempDict];
}
else {
Lessons *newLesson = (Lessons *)[NSEntityDescription insertNewObjectForEntityForName:@"Lessons" inManagedObjectContext:appDelegate.managedObjectContext];
newLesson.cards_count = [[tempListArray objectAtIndex:i] valueForKey:@"cards_count"];
newLesson.mTitle = [[tempListArray objectAtIndex:i] valueForKey:@"title"];
newLesson.sound_Url = [[tempListArray objectAtIndex:i] valueForKey:@"audio_url"];
newLesson.content_Id = [[tempListArray objectAtIndex:i] valueForKey:@"id"];
newLesson.username = appDelegate.userName;
newLesson.language = appDelegate.currentLanguage;
newLesson.mId = [NSNumber numberWithInt:i];
[tempDict setValue:newLesson forKey:@"lesson"];
[tempDict setValue: [[tempListArray objectAtIndex:i] objectForKey:@"image_url"] forKey:@"image_url"];
[listViewArray addObject:tempDict];
}
[tempDict release];
tempDict = nil;
}
if (![appDelegate.managedObjectContext save:&error]) {
NSLog(@"Core Data Error - %@", [error localizedDescription]);
}
// NSMutableArray *tempArray = [NSMutableArray arrayWithArray:listViewArray];
// [listViewArray removeAllObjects];
// [listViewArray addObjectsFromArray:[[tempArray reverseObjectEnumerator] allObjects]];
// tempArray = nil;
}
[tempListArray release];
}
[mListsTableView reloadData];
这是崩溃的代码，在 parser:foundObject 中调用:循环代码已被删除，因为每次下载新的 Json 对象时都会调用它。
[jsonStreamedData addObject:dict];
if (!listViewArray)
listViewArray = [[NSMutableArray alloc] init];
MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
NSError *error = nil;
[appDelegate.managedObjectContext reset];
NSManagedObjectContext *managedObjectContext = appDelegate.managedObjectContext;
NSFetchRequest *checkRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *lessonEntity = [NSEntityDescription entityForName:@"Lessons" inManagedObjectContext:managedObjectContext];
[checkRequest setEntity:lessonEntity];
NSPredicate *langPredicate = [NSPredicate predicateWithFormat:@"(language = %@)", appDelegate.currentLanguage];
NSPredicate *userPredicate = [NSPredicate predicateWithFormat:@"(username = %@)", appDelegate.userName];
NSPredicate *idPredicate = [NSPredicate predicateWithFormat:@"(content_Id = %@)", [dict valueForKey:@"id"]];
[checkRequest setPredicate:[NSCompoundPredicate andPredicateWithSubpredicates:[NSArray arrayWithObjects:langPredicate, userPredicate, idPredicate, nil]]];
NSArray *checkResults = [managedObjectContext executeFetchRequest:checkRequest error:&error];
[checkRequest release];
NSMutableDictionary *tempDict = [[NSMutableDictionary alloc] init];
if ([checkResults count]) {
Lessons *lessonObj = [checkResults objectAtIndex:0];
lessonObj.cards_count = [dict valueForKey:@"cards_count"];
lessonObj.mTitle = [dict valueForKey:@"title"];
lessonObj.sound_Url = [dict valueForKey:@"audio_url"];
lessonObj.mId = [NSNumber numberWithInt:jsonStreamedData.count - 1]; // This should be equivalent to i from the loop in the first code
[tempDict setValue:lessonObj forKey:@"lesson"];
[tempDict setValue: [dict objectForKey:@"image_url"] forKey:@"image_url"];
[listViewArray addObject:tempDict];
}
else {
Lessons *newLesson = (Lessons *)[NSEntityDescription insertNewObjectForEntityForName:@"Lessons" inManagedObjectContext:appDelegate.managedObjectContext];
newLesson.cards_count = [dict valueForKey:@"cards_count"];
newLesson.mTitle = [dict valueForKey:@"title"];
newLesson.sound_Url = [dict valueForKey:@"audio_url"];
newLesson.content_Id = [dict valueForKey:@"id"];
newLesson.username = appDelegate.userName;
newLesson.language = appDelegate.currentLanguage;
newLesson.mId = [NSNumber numberWithInt:jsonStreamedData.count - 1];
[tempDict setValue:newLesson forKey:@"lesson"];
[tempDict setValue: [dict objectForKey:@"image_url"] forKey:@"image_url"];
[listViewArray addObject:tempDict];
}
[tempDict release];
tempDict = nil;
if (![appDelegate.managedObjectContext save:&error]) {
ALog(@"Core Data Error - %@", [error localizedDescription]);
}
// NSMutableArray *tempArray = [NSMutableArray arrayWithArray:listViewArray];
// [listViewArray removeAllObjects];
// [listViewArray addObjectsFromArray:[[tempArray reverseObjectEnumerator] allObjects]];
// tempArray = nil;
//[self getListsLocally];
[mListsTableView reloadData];
最后，这是使用第二个 list 时崩溃的实际部分，在 tableView:cellForRowAtIndexPath: 顺便说一句，当 row == 1，而不是 row == 0 时，它会崩溃。由于某种原因，第 0 行还可以......它永远不会当然，有机会加载其他行。
titleLabel.text = [[[listViewArray objectAtIndex:indexPath.row] valueForKey:@"lesson"] valueForKey:@"mTitle"]; // CRASH!
labelCards.text = [NSString stringWithFormat:@"%@ Cards", [[[listViewArray objectAtIndex:indexPath.row] valueForKey:@"lesson"] valueForKey:@"cards_count"]];
if([[listViewArray objectAtIndex:indexPath.row] objectForKey:@"userImageObj"] == nil){
mImageView.backgroundColor = [UIColor grayColor];
if ([[listViewArray objectAtIndex:indexPath.row] objectForKey:@"isThreadLaunched"] == nil) {
[NSThread detachNewThreadSelector:@selector(loadImagesInBackground:) toTarget:self withObject:[NSNumber numberWithInt:indexPath.row]];
[[listViewArray objectAtIndex:indexPath.row] setObject:@"Yes" forKey:@"isThreadLaunched"];
}
}else {
mImageView.image = [[listViewArray objectAtIndex:indexPath.row] objectForKey:@"userImageObj"];
}
请您参考如下方法:
当您调用 reset 时，最有可能发生对象失效。在运行 fetch 之前在 managedObjectContext 上。调用reset使内存中的对象无效，但在保存之前不会删除它们。如果一个无效的托管对象被另一个对象(例如数组)保留，那么它将在保存后以无效的形式持续存在。当您运行提取时，提取返回无效对象，当您尝试访问它们的属性之一时会导致错误reset与撤消管理器一起使用时会被调用。它不是通用的“删除上下文”调用。如果要删除现有对象，则需要获取它们并显式删除它们。
您的代码还有其他一些问题。您调用release在 checkRequest即使您没有创建数组。这可能会导致数组随机消失。 listViewArray 也是如此似乎是一个类属性，但您从不使用访问器形式，例如self.listViewArray以确保适当的保留。
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