Question

我尝试使用NSFetchedResultsController和不同的部分在tableview中保存核心数据。

当我添加数据后出现错误：

CoreData：错误：严重的应用程序错误。抓住了例外   在核心数据更改处理期间。这通常是一个bug   NSManagedObjectContextObjectsDidChangeNotification的观察者。的 *    - [__ NSPlaceholderDictionary initWithObjects：forKeys：count：]：尝试使用userInfo（null）从对象[0]插入nil对象    由于未捕获的异常终止应用＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39; - [__NSPlaceholderDictionary   initWithObjects：forKeys：count：]：尝试从中插入nil对象   对象[0] *

第一次抛出调用堆栈：（0x181a05900 0x181073f80 0x1818f41a8 0x1818f4040 0x1000a9068 0x1000aa8d8 0x1835905a8 0x183505080   0x183504f48 0x183495108 0x1819aafc4 0x1819aa7e4 0x1819aa564   0x181a0fde4 0x1818eb0f4 0x1822dad2c 0x18349506c 0x1835098d0   0x18349378c 0x183492240 0x1000aa3a0 0x18672fe50 0x1868b34a4   0x18672fe50 0x18672fdcc 0x186717a88 0x186717bd4 0x18672f6e4   0x18672f314 0x186727e30 0x1866f84cc 0x1866f6794 0x1819bcefc   0x1819bc990 0x1819ba690 0x1818e9680 0x182df8088 0x186760d90   0x10004c23c 0x18148a8b8）libc ++ abi.dylib：终止未捕获   类型NSException`
的异常

我的代码：

MyDetailData* MyDetail = [NSEntityDescription insertNewObjectForEntityForName:@"MyDetailData" inManagedObjectContext:self._privateObjectContext];
[MyDetail setKategorie: NSLocalizedString(@"Test", nil)];
NSError *error = nil;
if (![MyDetail.managedObjectContext save:&error]) {
      NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}

在iOS6下，所有代码都很好

这是我的NSFetchedResultsController

- (NSFetchedResultsController *)fetchedResultsController2 {

    if (fetchedResultsController2 != nil) {
       return fetchedResultsController2;
    }

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription     entityForName:@"MyDetailData" inManagedObjectContext:_privateObjectContext];
    [request setEntity:entity];

    NSSortDescriptor *KategorieDescriptor = [[NSSortDescriptor alloc] initWithKey:@"kategorie" ascending:YES];
    NSSortDescriptor *oderDescriptor = [[NSSortDescriptor alloc] initWithKey:@"order" ascending:YES];
    NSSortDescriptor *nameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];

    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:KategorieDescriptor,oderDescriptor,nameDescriptor, nil];
    [request setSortDescriptors:sortDescriptors];


    NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:_privateObjectContext sectionNameKeyPath:@"kategorie" cacheName:nil];
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController2 = aFetchedResultsController;

    return fetchedResultsController2;

}

TableView委托

numberOfSectionsInTableView
numberOfRowsInSection
NSFetchedResultsController didChangeObject - ＆gt; NSFetchedResultsChangeInsert
NSFetchedResultsController didChangeSection - ＆gt; NSFetchedResultsChangeInsert

调用并包含正确的信息 - 这是相关代码：

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return [[fetchedResultsController2 sections] count];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController2 sections] objectAtIndex:section];
    return [sectionInfo numberOfObjects];
}


- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {

    if (userDrivenDataModelChange) return;

    switch(type) {
        case NSFetchedResultsChangeInsert:
            [self.tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeDelete:
            [self.tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeUpdate: {
            [self configureCell:[self.tv cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];

            NSString *sectionKeyPath = [controller sectionNameKeyPath];
            if (sectionKeyPath == nil)
                break;

            NSManagedObject *changedObject = [controller objectAtIndexPath:indexPath];
            NSArray *keyParts = [sectionKeyPath componentsSeparatedByString:@"."];
            id currentKeyValue = [changedObject valueForKeyPath:sectionKeyPath];
            for (int i = 0; i < [keyParts count] - 1; i++) {
                NSString *onePart = [keyParts objectAtIndex:i];
                changedObject = [changedObject valueForKey:onePart];
            }
            sectionKeyPath = [keyParts lastObject];
            NSDictionary *committedValues = [changedObject committedValuesForKeys:nil];

            if ([[committedValues valueForKeyPath:sectionKeyPath] isEqual:currentKeyValue])
                break;

            NSUInteger tableSectionCount = [self.tv numberOfSections];
            NSUInteger frcSectionCount = [[controller sections] count];
            if (tableSectionCount != frcSectionCount) {
                // Need to insert a section
                NSArray *mysections = controller.sections;
                NSInteger newSectionLocation = -1;
                for (id oneSection in mysections) {
                    NSString *sectionName = [oneSection name];
                    if ([currentKeyValue isEqual:sectionName]) {
                        newSectionLocation = [mysections indexOfObject:oneSection];
                        break;
                    }
                }
                if (newSectionLocation == -1)
                    return; // uh oh

                if (!((newSectionLocation == 0) && (tableSectionCount == 1) && ([self.tv numberOfRowsInSection:0] == 0)))
                    [self.tv insertSections:[NSIndexSet indexSetWithIndex:newSectionLocation] withRowAnimation:UITableViewRowAnimationFade];
                NSUInteger indices[2] = {newSectionLocation, 0};
                newIndexPath = [[NSIndexPath alloc] initWithIndexes:indices length:2];
            }


        }

        case NSFetchedResultsChangeMove:
            [self.tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                             withRowAnimation:NO];
            [self.tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
                             withRowAnimation:NO];
            break;
        default:
            break;
    }
}


- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
    switch(type) {

        case NSFetchedResultsChangeInsert:
            if (!((sectionIndex == 0) && ([self.tv numberOfSections] == 1)))
                [self.tv insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeDelete:
            if (!((sectionIndex == 0) && ([self.tv numberOfSections] == 1) ))
                [self.tv deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeMove:
            break;
        case NSFetchedResultsChangeUpdate: 
            break;
        default:
            break;
    }
}

想法出了什么问题？

Answer 1

问题解决了。在

didChangeObject

at

 case NSFetchedResultsChangeMove

我改变了行

 [self.tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                         withRowAnimation:NO];

  [self.tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
                           withRowAnimation:NO];

到

   if (indexPath && newIndexPath) {
                 [self.tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                         withRowAnimation:NO];

                 [self.tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
                           withRowAnimation:NO];
  } else {
                 NSLog(@"A table item was moved");
  }

无法保存核心数据

1 个答案: