有时我在同一个地方有coredata这个错误。有时它确定，在其他时间我有这个错误。这是什么意思？我找不到任何关于它的信息:(
抱歉我的英语：）
conflictList =（ “NSMergeConflict（0xd447640）for NSManagedObject（0xd41b370）with objectID'0xd41b500'with oldVersion = 4 and newVersion = 5 and old object snapshot = {\ n album = \”{（\ n）} \“; \ n \ n audios = \” {（\ n）} \“; \ n bdate = \”\“; \ n city = \”\“; \ n country = \”\“; \ n dialog = \”{（\ n）} \“ ; \ n domain = \“white.smoke \”; \ n faculty = 0; \ n facultyName = \“\”; \ n firstName = White; \ n graduation = 0; \ n homePhone = \“\”; \ n isFriend = 1; \ n isMe = 0; \ n lastName = Smoke; \ n mobilePhone = \“\”; \ n nickName = \“\”; \ n online = 1; \ n photo = \“\”; \ n photoBig = \“\”; \ n photoComments = \“{（\ n）} \”; \ n photoMedium = \“\”; \ n photoRec = \“http://cs10609.vkontakte.ru/u79185807 /e_8c949409.jpg\";\n photos = \“{（\ n（实体：照片; id：0xd482c50;数据：{\ n aid = 121594781; \ n album = nil; \ n comments = \\”\\ “; \ n commentsCount = 0; \ n created = \\”2010-12-10 03:45:01 GMT \\“; \ n owner = \\”0xd41b500 \\“; \ n \\”owner_id \\ “= 79185807; \ n照片Number = 0; \ n pid = 196997145; \ n src = \\“http://cs10609.vkontakte.ru/u79185807/121594781/m_ \\”; \ n \\“src_big \\”= \\“http ：//cs10609.vkontakte.ru/u79185807/121594781/x_ \\“; \ n \\”src_small \\“= \\”http：//cs10609.vkontakte.ru/u79185807/121594781/s_ \\“; \ n \\“src_xbig \\”= nil; \ n \\“src_xxbig \\”= nil; \ n wallRel = \\“0xd480840 \\”; \ n}），\ n（实体：照片; id：0xd431570;数据：{\ n aid = 121594781; \ n album = nil; \ n comments = \\“\\”; \ n commentsCount = 0; \ n created = \\“2010-12-10 03:43:01 GMT \\“; \ n owner = \\”0xd41b500 \\“; \ n \\”owner_id \\“= 79185807; \ n photosNumber = 0; \ n pid = 196997029; \ n src = \\”http：/ /cs10609.vkontakte.ru/u79185807/121594781/m_\\";\n \\“src_big \\”= \\“http：//cs10609.vkontakte.ru/u79185807/121594781/x_ \\”; \ n \\“src_small \\”= \\“http：//cs10609.vkontakte.ru/u79185807/121594781/s_ \\”; \ n \\“src_xbig \\”= nil; \ n \\“src_xxbig \\ “= nil; \ n wallRel = \\”0xd42d500 \\“; \ n}）\ n）} \”; \ n rate = \“ - 19 \”; \ n sex = 0; \ nstatuses = \“ {（\ n）} \“; \ n时区= 0; \ n uid = 79185807; \ n university = 0; \ n universityName = \”\“; \ n videos = \”{（\ n）} \“ ; \ n wall = \“{（\ n）} \”; \ n wallPostsCount = 0; \ n wallReplies = \“{（\ n（实体：WallReply; id：0xd448270;数据:) \ n）} \” ; \ n wallSender = \“{（\ n）} \”; \ n}和新缓存的行= {\ n bdate = \“\”; \ n city = \“\”; \ n country = \“\ “; \ n domain = \“white.smoke \”; \ n faculty = 0; \ n facultyName = \“\”; \ n firstName = White; \ n graduation = 0; \ n homePhone = \“\”; \ n isFriend = 1; \ n isMe = 0; \ n lastName = Smoke; \ n mobilePhone = \“\”; \ n nickName = \“\”; \ n online = 1; \ n photo = \“\”; \ n photoBig = \“\”; \ n photoMedium = \“\”; \ n photoRec = \“http：//cs10609.vkontakte.ru/u79185807/e_8c949409.jpg \”; \ n rate = \“ - 19 \ “; \ n sex = 0; \ n timezone = 0; \ n uid = 79185807; \ n university = 0; \ n universityName = \”\“; \ n wallPostsCount = 0; \ n}” ）;
答案 0 :(得分：32)
当您的数据库从两个不同的位置更改，然后从两个不同的位置保存时，有时会导致合并冲突;在某些情况下，更改可能会影响相同的对象或属性，Core Data不会自动覆盖它们，因为这可能会破坏有价值的数据。
有几个选择：
答案 1 :(得分：8)
我在保存上下文时遇到了相同的合并冲突。请参阅apple doc here
我使用NSMergePolicy
解决了冲突- (BOOL)resolveConflicts:(NSArray *)list error:(NSError **)error
在创建NSMergePolicy对象时将policyType设置为NSOverwriteMergePolicyType
NSOverwriteMergePolicyType：指定一个策略，用于覆盖冲突中已更改对象的持久存储中的状态。
`
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
NSArray * conflictListArray = (NSArray*)[[error userInfo] objectForKey:@"conflictList"];
NSLog(@"conflict array: %@",conflictListArray);
NSError * conflictFixError = nil;
if ([conflictListArray count] > 0) {
NSMergePolicy *mergePolicy = [[NSMergePolicy alloc] initWithMergeType:NSOverwriteMergePolicyType];
if (![mergePolicy resolveConflicts:conflictListArray error:&conflictFixError]) {
NSLog(@"Unresolved conflict error %@, %@", conflictFixError, [conflictFixError userInfo]);
NSLog(@"abort");
abort();
}
} }
答案 2 :(得分：8)
简而言之 - 启用合并政策将此添加到您的MOC设置：
目标-C
[_managedObjectContext setMergePolicy:[[NSMergePolicy alloc] initWithMergeType:NSMergeByPropertyObjectTrumpMergePolicyType]];
夫特
lazy var managedObjectContext: NSManagedObjectContext? = {
let coordinator = self.persistentStoreCoordinator
if coordinator == nil {
return nil
}
var managedObjectContext = NSManagedObjectContext()
managedObjectContext.persistentStoreCoordinator = coordinator
//add this line
managedObjectContext.mergePolicy = NSMergePolicy(mergeType: NSMergePolicyType.MergeByPropertyObjectTrumpMergePolicyType);
return managedObjectContext
}()
答案 3 :(得分：1)
它正在解决，也许:) 例如，您有以下代码，它们存在于N个对象中（每个对象都在单独的线程中并且在同一时间（+ -10ms）创建）：
[coreObject addLinkedObject:linkedObject1];
在上下文中处理例程的时间约为70毫秒。 如果您只是将NSMergePolicy设置为（例如）： NSOverwriteMergePolicy ，您将拥有Last-In-Changes：只有最后一个对象将添加链接，因为每个上下文都是持久存储的内存快照。因此，每个快照都是在例程对象创建的时刻创建的。 70ms处理时间滞后导致 coreObject 的信息太旧，保存时。换句话说，您将只有一个保存的链接或合并错误。当然，您可以订阅NSManagedObjectContextObjectsDidChangeNotification但在这种情况下您将拥有N！订阅关系或者您可以在主线程中以明星方式跨主要上下文订阅，但有时它不起作用（我使用的是MagicalRecord，版权所有2011 Magical Panda Software LLC。）。 我的解决方案是在保存之前重新读取关键coreObject以及使用合适的合并策略：
@synchronized (self) {
if ([context hasChanges]) {
if (needRefresh) {
[context refreshObject:coreObject mergeChanges:NO];
[coreObject addLinkedObject:linkedObject1];
}
NSError *err = nil;
[context save:&err];
if (err) {
NSLog(@"Error Saving Linked Object: %@", [err userInfo]);
[context rollback];
}
}
}
在这种情况下，风险很小。
答案 4 :(得分：1)
快捷键4
private(set) lazy var mainContext: NSManagedObjectContext = {
let context = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
context.parent = privateContext
context.mergePolicy = NSMergePolicy(merge: .overwriteMergePolicyType)
// Or we can use Trumping
// .mergeByPropertyObjectTrumpMergePolicyType
// .mergeByPropertyStoreTrumpMergePolicyType
// Rolling back is another option
// .rollbackMergePolicyType
return context
}()