Question

我正在尝试将pdf阅读器应用中的书签同步到服务器。书签将保存到核心数据，然后同步到服务器。

但是，在尝试使用restkit同步核心数据的同时尝试同步到核心数据时，我遇到了异常。我得到的错误：

CoreData could not fulfill a fault for '0x11940014b <x-coredata://5F7F2CE2-4C88-4D87-9C96-B475DC029FCA/Bookmark/p1125>'

单击删除按钮时调用的代码：

- (BOOL)removeBookmarkForPage:(NSUInteger)page inBook:(IBBook *)book
{
    __block BOOL isSuccess = NO;

    dispatch_sync(_bookmarkQueue, ^{
        [[[IBCoreDataManager sharedManager] moc] performBlockAndWait:^() {
            NSMutableSet *bookmarks = [_bookmarkCache objectForKey:book.isbn];
            [bookmarks enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
                IBBookmark *bookmark = (IBBookmark *)obj;
                if ([bookmark.pageNumber integerValue] == page) {
                    bookmark.action = kAnnotationIsRemovedKey;
                }
            }];

            [_bookmarkCache setObject:bookmarks forKey:book.isbn];
        }];
    });

    [[NSNotificationCenter defaultCenter] postNotificationName:IBBookmarksDidChangeNotification object:self];

    return isSuccess;
}

bookmark.action = kAnnotationIsRemovedKey;行是投射异常的行。

只有在发生同步时才会转换异常（调用下面的方法）。在同步时，它会将缓存保存到coredata：

- (BOOL)saveAllBookmarksToCoreDataForBook:(IBBook *)book withError:(NSError **)error
{
    __block BOOL isSuccess = YES;

    dispatch_sync(_bookmarkQueue, ^{
        [[[IBCoreDataManager sharedManager] moc] performBlockAndWait:^() {
            NSMutableSet *bookmarksInCache = [_bookmarkCache objectForKey:book.isbn];
            NSMutableSet *annotations = [NSMutableSet set];
            if (bookmarksInCache) {
                [book.userAnnotations enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
                    if (![obj isKindOfClass:[IBBookmark class]]) {
                        [annotations addObject:obj];
                    }
                }];
                [annotations unionSet:bookmarksInCache];
                book.userAnnotations = annotations;
            }

            NSError *coreDataError;
            [[IBCoreDataManager sharedManager] saveToPersistantStoreWithError:&coreDataError];
            if (coreDataError) {
                isSuccess = NO;
                *error = coreDataError;
            }
        }];
    });

    return isSuccess;
}

@end

_bookmarkQueue定义为：

_bookmarkQueue = dispatch_queue_create([[NSString stringWithFormat:@"myAppName.%@", self] UTF8String], DISPATCH_QUEUE_SERIAL);

_moc定义为：

_moc = self.objectManager.managedObjectStore.mainQueueManagedObjectContext;

关于如何解决的任何想法？

更新

我也遇到了这个错误：

 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Illegal attempt to establish a relationship 'userAnnotations' between objects in different contexts (source = <IBBook: 0x10045eb90> (entity: Book; id: 0x240004b <x-coredata://76F2C086-D7DE-4210-B0C1-AA49DC5802D3/Book/p9> ;

destination = <IBBookmark: 0x102fa10b0> (entity: Bookmark; id: 0x22a40014b <x-coredata://76F2C086-D7DE-4210-B0C1-AA49DC5802D3/Bookmark/p2217> ; data: <fault>))'

在book.userAnnotations = annotations; <{1}} <{1}}行中的

NSCoreDataException：CoreData无法解决问题

0 个答案: