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我正在開發一個應用程序，我有用戶，每個用戶都有跟隨者的多對多關係。我目前在保存新用戶對象時遇到了一些問題。該應用程序在managedObjectContext save上分割。我收到以下錯誤：核心數據NSValidationErrorObject，導致崩潰
Unresolved error Error Domain=NSCocoaErrorDomain Code=1560 "The operation couldn’t be completed. (Cocoa error 1560.)" UserInfo=0x8580640 {NSDetailedErrors=(
"Error Domain=NSCocoaErrorDomain Code=1550 \"The operation couldn\U2019t be completed. (Cocoa error 1550.)\" UserInfo=0x85820c0 {NSValidationErrorObject=<User: 0x7575870> (entity: User; id: 0x75757c0
NSValidationErrorKey=followers, NSLocalizedDescription=The operation couldn\U2019t be completed. (Cocoa error 1550.), NSValidationErrorValue=Relationship 'followers' on managed object (0x7575870) <User: 0x7575870> (entity: User; id: 0x75757c0
"Error Domain=NSCocoaErrorDomain Code=1550 \"The operation couldn\U2019t be completed. (Cocoa error 1550.)\" UserInfo=0x8586830 {NSValidationErrorObject=<User: 0x7571ec0> (entity: User; id: 0x7571f00
"Error Domain=NSCocoaErrorDomain Code=1550 \"The operation couldn\U2019t be completed. (Cocoa error 1550.)\" UserInfo=0x858e820 {NSValidationErrorObject=<User: 0x7573120> (entity: User; id: 0x7573160
[...]
我無法真正弄清楚是什麼導致了這個崩潰。我的關係是這樣的：
該模型有一個自定義NSManagedObject子類與@property (nonatomic, retain) NSSet *followers;。正如我所說，我不確定是什麼造成了這一點，所以任何指導或想法都會很棒！
更新
該方法的應用程序崩潰：
- (void)saveContext
{
NSError *error = nil;
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
[managedObjectContext setMergePolicy:NSMergeByPropertyObjectTrumpMergePolicy];
if (managedObjectContext != nil) {
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
// Uncomment "abort" makes it work, but I still get the error.
abort();
}
}
}
更新2
更多來自我的模型代碼，以及如何使用它們：
如何我設置我的獲取請求控制器：
- (NSSortDescriptor *)sortDescriptorForFetchRequest
{
NSSortDescriptor *sortDescriptor;
if ([self.postType isEqualToString:@"following"] || [self.postType isEqualToString:@"followers"]) {
sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"userId" ascending:NO];
} else {
sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"postId" ascending:NO];
}
return sortDescriptor;
}
- (NSEntityDescription *)entityForFetchRequest
{
NSEntityDescription *entity;
if ([self.postType isEqualToString:@"followers"] || [self.postType isEqualToString:@"following"]) {
entity = [NSEntityDescription entityForName:@"User" inManagedObjectContext:[self.appController managedObjectContext]];
} else {
entity = [NSEntityDescription entityForName:@"Post" inManagedObjectContext:[self.appController managedObjectContext]];
}
return entity;
}
- (void)setUpFetchResultController
{
if (self.fetchedResultsController == nil) {
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity:[self entityForFetchRequest]];
[fetchRequest setPredicate:[self predicateBasedOnPostType:self.postType]];
NSArray *sortDescriptors = @[[self sortDescriptorForFetchRequest]];
[fetchRequest setSortDescriptors:sortDescriptors];
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[self.appController managedObjectContext] sectionNameKeyPath:nil cacheName:[self cacheName]];
self.fetchedResultsController.delegate = self;
}
}
而且我的模型，User：
+ (void)addUserFromDictionary:(NSDictionary *)dictionary forUser:(User *)user inManagedObjectContext:(NSManagedObjectContext*)moc follower:(BOOL)follower following: (BOOL)following
{
User *localUser;
if (follower) {
if ([dictionary isKindOfClass:[NSArray class]]) {
NSEnumerator *enumerator = [dictionary objectEnumerator];
id value;
while (value = [enumerator nextObject]) {
localUser = [self parseUserFromDictionary:value inManagedObjectContext:moc];
if ([self user:localUser alreadyFollowingUser:user inManagedObjectContext:moc] == NO) {
[user addFollowersObject:localUser];
[localUser addFollowingObject:user];
}
}
}
}
}
+ (User *)parseUserFromDictionary:(NSDictionary *)dictionary inManagedObjectContext:(NSManagedObjectContext*)moc
{
NSNumberFormatter *numberFormatter= [[NSNumberFormatter alloc] init];
NSNumber * userId = [numberFormatter numberFromString:(NSString *)[dictionary valueForKey:@"id"]];
User *user;
if ([self userAlreadyExist:userId inManagedObjectContext:moc] == NO) {
NSEntityDescription *userDescription = [NSEntityDescription entityForName:@"User" inManagedObjectContext:moc];
user = [[User alloc] initWithEntity:userDescription insertIntoManagedObjectContext:moc];
} else {
user = [User findUser:userId inManagedObjectContext:moc];
}
user.name = [dictionary valueForKey:@"name"];
[...]
return user;
}
User->跟隨樣子的關係是什麼？它看起來像你設置了一些不滿足的約束 – 2013-03-07 21:40:53
它看起來跟追隨者一樣。錯誤的圖片。 – Anders 2013-03-09 08:51:01
你確定你已經清除了你的應用程序和一切，並且你的sqlite文件與你定義的xcdatamodeld文件相匹配嗎？我沒有看到您提供的代碼和方案中的錯誤。 – 2013-03-11 08:11:44