我有一個實體A
,它與B
有關係。CoreData無法完成未修改關係的錯誤
這裏是從CoreData取出一個陣列:
NSPredicate * predicate = [NSPredicate predicateWithFormat:@"isSynchronized = NO"];
NSManagedObjectContext *context = [NSManagedObjectContext MR_contextForCurrentThread];
NSArray * newWordsToSynchronize = [A MR_findAllWithPredicate:predicate inContext:context];
NSMutableArray * newWordsParameters = [NSMutableArray arrayWithCapacity:[asToSynchronize count]];
[newWordsToSynchronize enumerateObjectsUsingBlock:^(A * a, NSUInteger idx, BOOL * stop) {
NSLog(@"============= may have some problem ============");
NSLog(@"[a hasFaultForRelationshipNamed:@\"b\"] = %d", [a hasFaultForRelationshipNamed:@"b"]);
NSLog(@"a.word = %@", a.word);
NSLog(@"a.b.objectID = %@", a.b.objectID);
NSLog(@"a.managedObjectContext = %@", a.managedObjectContext);
NSLog(@"a.b.managedObjectContext = %@", [a.b managedObjectContext]);
NSLog(@"a.b.managedObjectContext = %@", [a.b managedObjectContext]);
NSLog(@"a.managedObjectContext = %@", a.managedObjectContext);
NSDictionary *paramDictionary = @{
@"nbook" : a.b.name,
@"lang" : a.lang,
...
};
[newWordsParameters addObject:paramDictionary];
}];
的[a.b managedObjectContext]
方法可以返回nil時我把它在第二時間,然後該應用去崩潰。
崩潰日誌從控制檯:
2014-01-20 14:29:14.561 MyApp[10563:2e07] a.b.objectID = 0x1754e940 <x-coredata://DFC4F956-D5AC-4264-8717-C07090CA9547/B/p1>
2014-01-20 14:29:14.561 MyApp[10563:2e07] a.managedObjectContext = <NSManagedObjectContext: 0x1754bc00>
2014-01-20 14:29:14.561 MyApp[10563:2e07] a.b.managedObjectContext = <NSManagedObjectContext: 0x1754bc00>
2014-01-20 14:29:14.562 MyApp[10563:2e07] a.b.managedObjectContext = (null)
*** Terminating app due to uncaught exception 'NSObjectInaccessibleException', reason: 'CoreData could not fulfill a fault for '0x1754e940 <x-coredata://DFC4F956-D5AC-4264-8717-C07090CA9547/B/p1>''
*** First throw call stack:
(
0 CoreFoundation 0x037495e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x034cc8b6 objc_exception_throw + 44
2 CoreData 0x031a233b _PFFaultHandlerLookupRow + 2715
3 CoreData 0x031a1897 -[NSFaultHandler fulfillFault:withContext:forIndex:] + 39
4 CoreData 0x031a1473 _PF_FulfillDeferredFault + 259
5 CoreData 0x031a12c6 _sharedIMPL_pvfk_core + 70
6 CoreData 0x031e7130 _pvfk_5 + 32
7 MyApp 0x00181b00 __68-[CichangAHTTPEngine synchronizeAsOnCompletion:failure:]_block_invoke + 1760
8 CoreFoundation 0x037435eb __NSArrayEnumerate + 571
9 CoreFoundation 0x03743196 -[NSArray enumerateObjectsWithOptions:usingBlock:] + 102
10 CoreFoundation 0x037430a5 -[NSArray enumerateObjectsUsingBlock:] + 53
11 MyApp 0x0018105b -[CichangAHTTPEngine synchronizeAsOnCompletion:failure:] + 1179
12 MyApp 0x00185d9e __65-[CichangAHTTPEngine downloader:didFinishedDownloadObject:]_block_invoke_3 + 2030
13 libdispatch.dylib 0x040717f8 _dispatch_call_block_and_release + 15
14 libdispatch.dylib 0x040864b0 _dispatch_client_callout + 14
15 libdispatch.dylib 0x04074eeb _dispatch_root_queue_drain + 287
16 libdispatch.dylib 0x04075137 _dispatch_worker_thread2 + 39
17 libsystem_pthread.dylib 0x04412dab _pthread_wqthread + 336
18 libsystem_pthread.dylib 0x04416cce start_wqthread + 30
)
libc++abi.dylib: terminating with uncaught exception of type _NSCoreDataException
我發現B
將首先[a.b managedObjectContext]
呼叫之後被釋放。
我認爲這主要是由Core Data 1550錯誤引起的(如果我沒有調用[a.b managedObjectContext],Core Data會報告「操作無法完成(Cocoa error 1550.)」)。但是,可能會導致1550錯誤以及如何解決它?
1550錯誤報告:
Error Domain=NSCocoaErrorDomain Code=1550 "The operation couldn’t be completed. (Cocoa error 1550.)" UserInfo=0x167269c0 {NSLocalizedDescription=The operation couldn’t be completed. (Cocoa error 1550.), Dangling reference to an invalid object.=null, NSValidationErrorObject=<A: 0x16bab420> (entity: A; id: 0x16baae50 <x-coredata://A85EE9AB-97C1-43C1-B92E-A6C906F0C1A8/A/p168> ; data: {
date = "2014-01-21 02:32:00 +0000";
expect = "2014-01-21 02:31:59 +0000";
isSynchronized = 1;
lang = en;
last = "2014-01-21 02:01:59 +0000";
level = 1;
b = "0x16bab460 <x-coredata://A85EE9AB-97C1-43C1-B92E-A6C906F0C1A8/B/p1>";
status = "-1";
studycount = 0;
trans = "v. \U6d4b\U91cf\Uff0c\U6743\U8861 ";
word = measure;
}), NSAffectedObjectsErrorKey=(
"<B: 0x16babd70> (entity: B; id: 0x16bab460 <x-coredata://A85EE9AB-97C1-43C1-B92E-A6C906F0C1A8/B/p1> ; data: <fault>)"
), NSValidationErrorKey=newWordBook, NSValidationErrorValue=<B: 0x16babd70> (entity: B; id: 0x16bab460 <x-coredata://A85EE9AB-97C1-43C1-B92E-A6C906F0C1A8/B/p1> ; data: <fault>), NSValidationErrorShouldAttemptRecoveryKey=true}
如果1550錯誤發生, 「CoreData不能履行故障」 墜毀會更easer造成的。
有沒有後臺操作刪除對象?這些對象是否一直保存到商店/磁盤? –
當應用程序在前臺運行時,我沒有刪除操作,實體「B」永遠不會被刪除。 –
從B到A有反比關係嗎?代表這兩種關係的屬性是怎樣的? – eofster