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我有一些代碼將課程下載爲JSON，解析它們並將它們放入核心數據。然後它們顯示在UITableView中。目前，當用戶有很多課程時，連接有時會超時。所以我試圖解析這些課程（使用SBJson）並將它們一次添加到tableview中。核心數據NSObjectInaccessibleException NSManagedObject已失效
兩個代碼基本上是相同的，但新的代碼產生時的tableView的東西踢崩潰，並顯示錯誤
"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.'"
我想知道有什麼區別這兩者之間代碼清單可能會導致此錯誤。原始代碼在循環中創建每個核心數據對象，但新代碼在下載時創建每個核心數據對象。 listViewArray是用來填充UITableView的數組。
我使用SBJsonStreamParser和SBJsonStreamParserAdapter解析JSON，因爲它的用武之地。
我有一個工作的實施（未顯示），基本上調用每一個接收到新的對象時，下面的原代碼（運行通過每次接收到的對象的完整循環）。不過，我想知道是什麼導致了錯誤，而不僅僅是讓事情起作用。
這是原來的非流碼，堪稱connectionDidFinishLoading：
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];
這裏是崩潰的代碼，稱爲解析器：foundObject：循環代碼已被刪除，因爲這就是所謂的每一次下載新的Json對象。
[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];
最後，這裏是使用第二上市的時候，在那的tableView崩潰的實際部分：的cellForRowAtIndexPath：順便說一下，它崩潰的時候排== 1，不排== 0，出於某種原因，排0沒問題......當然，它從來沒有機會加載其他行。
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"];
}