Ios 从子上下文分配对象时试图建立关系的非法尝试
我花了几个小时试图解决父子核心数据模型的问题。但让我们从头开始。我有主上下文和子上下文，主上下文是Ios 从子上下文分配对象时试图建立关系的非法尝试,ios,objective-c,core-data,nsmanagedobjectcontext,Ios,Objective C,Core Data,Nsmanagedobjectcontext,我花了几个小时试图解决父子核心数据模型的问题。但让我们从头开始。我有主上下文和子上下文，主上下文是.parentContext - (NSManagedObjectContext *)mainContext { if (!_mainContext) { _mainContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType]; [_m
.parentContext- (NSManagedObjectContext *)mainContext {
if (!_mainContext) {
_mainContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
[_mainContext setPersistentStoreCoordinator:self.persistentStoreCoordinator];
}
return _mainContext;
}
- (NSManagedObjectContext *)childContext {
if (!_childContext) {
_childContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_childContext setParentContext:self.mainContext];
}
return _childContext;
}
Entity2 *entity2 = [NSEntityDescription insertNewObjectForEntityForName:NSStringFromClass([Entity2 class])
inManagedObjectContext:_stack.childContext];
Entity1 *entity1 = [NSEntityDescription insertNewObjectForEntityForName:NSStringFromClass([Entity1 class])
inManagedObjectContext:_stack.mainContext];
entity1.arg1 = @"ABC";
entity1.arg2 = @"DEF";
entity1entity2[entity1 setEntity2:entity2];
[_stack.childContext performBlock:^{
NSError *error;
if (![_stack.childContext save:&error]) {
NSLog(@"Error: %@", error);
}
[_stack.mainContext performBlock:^{
NSError *error;
if (![_stack.mainContext save:&error]) {
NSLog(@"Error: %@", error);
}
[entity1 setEntity2:entity2];
}];
}];
[entity1 setEntity2:entity2]2014-06-22 08:48:24.444 MultiContextualCoreData[1324:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Illegal attempt to establish a relationship 'entity1' between objects in different contexts (source = <Entity2: 0x8c81570> (entity: Entity2; id: 0x8c80000 <x-coredata:///Entity2/tC31696AE-0A0A-424E-9C8E-1E19085F3FB43> ; data: {
entity1 = nil;
}) , destination = <Entity1: 0x8c80200> (entity: Entity1; id: 0x8c80250 <x-coredata:///Entity1/tC31696AE-0A0A-424E-9C8E-1E19085F3FB42> ; data: {
arg1 = ABC;
arg2 = DEF;
entity2 = nil;
}))'
*** First throw call stack:
(
0 CoreFoundation 0x01b541e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x018d38e5 objc_exception_throw + 44
2 CoreData 0x00293b7e _PFManagedObject_coerceValueForKeyWithDescription + 3614
3 CoreData 0x002614e9 _sharedIMPL_setvfk_core + 185
4 CoreData 0x0027ada7 _svfk_0 + 39
5 MultiContextualCoreData 0x00002d4a -[AppDelegate test] + 554
6 MultiContextualCoreData 0x00002acd -[AppDelegate application:didFinishLaunchingWithOptions:] + 605
7 UIKit 0x0058d14f -[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 309
8 UIKit 0x0058daa1 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1810
9 UIKit 0x00592667 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824
10 UIKit 0x005a6f92 -[UIApplication handleEvent:withNewEvent:] + 3517
11 UIKit 0x005a7555 -[UIApplication sendEvent:] + 85
12 UIKit 0x00594250 _UIApplicationHandleEvent + 683
13 GraphicsServices 0x03a07f02 _PurpleEventCallback + 776
14 GraphicsServices 0x03a07a0d PurpleEventCallback + 46
15 CoreFoundation 0x01acfca5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
16 CoreFoundation 0x01acf9db __CFRunLoopDoSource1 + 523
17 CoreFoundation 0x01afa68c __CFRunLoopRun + 2156
18 CoreFoundation 0x01af99d3 CFRunLoopRunSpecific + 467
19 CoreFoundation 0x01af97eb CFRunLoopRunInMode + 123
20 UIKit 0x00591d9c -[UIApplication _run] + 840
21 UIKit 0x00593f9b UIApplicationMain + 1225
22 MultiContextualCoreData 0x00002efd main + 141
23 libdyld.dylib 0x0219b701 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
2014-06-22 08:48:24.444多上下文编码数据[1324:60b]***由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“非法尝试在不同上下文中的对象之间建立关系“entity1”（源=（实体：Entity2；id:0x8c80000；数据：{
实体1=无；
})，destination=（实体：Entity1；id:0x8c80250；数据：{
arg1=ABC；
arg2=DEF；
实体2=无；
}))'
***第一次抛出调用堆栈：
(
0 CoreFoundation 0x01b541e4例外预处理+180
1 libobjc.A.dylib 0x018d38e5 objc_异常_抛出+44
2个CoreData 0x00293b7e _PFManagedObject_强制评估值forkey，带说明+3614
3 CoreData 0x002614e9_sharedIMPL_setvfk_core+185
4 CoreData 0x0027ada7_svfk_0+39
5多上下文编码数据0x00002d4a-[AppDelegate测试]+554
6多上下文数据0x00002acd-[AppDelegate应用程序：didFinishLaunchingWithOptions:+605
7 UIKit 0x0058d14f-[UIApplication\u处理的远程回调，带选项：isSuspended:restoreState:+309
8 UIKit 0x0058daa1-[UIApplication\u CallInitializationDelegatesForRL:有效负载：挂起：][1810
9 UIKit 0x00592667-[UIApplication-runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:+824
10 UIKit 0x005a6f92-[UIApplication handleEvent:withNewEvent:][3517
11 UIKit 0x005a7555-[UIApplication sendEvent:+85
12 UIKit 0x00594250 _UIApplicationHandleEvent+683
13图形服务0x03a07f02 _PurpleEventCallback+776
14图形服务0x03a07a0d PurpleEventCallback+46
15 CoreFoundation 0x01acfca5\uuuuu CFRUNLOOP\u正在调用\uu OUT\uu以执行\uu功能\uuuu+53
16 CoreFoundation 0x01acf9db\uuu CFRunLoopDoSource1+523
17 CoreFoundation 0x01afa68c\uuu CFRunLoopRun+2156
18 CoreFoundation 0x01af99d3 CFRunLoopRunSpecific+467
19 CoreFoundation 0x01af97eb CFRUNLOOPSRUNINMODE+123
20 UIKit 0x00591d9c-[UIU应用程序运行]+840
21 UIKit 0x00593f9b UIApplicationMain+1225
22多上下文编码数据0x00002efd main+141
23 libdyld.dylib 0x0219b701启动+1
)
libc++abi.dylib:以NSException类型的未捕获异常终止
（lldb）
提前感谢您的帮助。问题是两个对象必须属于同一上下文才能在它们之间建立关系。在您的例子中，其中一个上下文有一个私有类型，它有自己的工作队列，其中主上下文在主队列上工作。这是一种防止您在将来遇到并发问题的方法 可能的解决办法是
- 创建
，保存主上下文，使用entity1
在子上下文中检索它，或者如果提取请求更有意义，则只在managedObjectID
和entity1
在同一上下文中时才建立关系entity2 - 或者，如果逻辑允许，简单地在同一上下文中创建两个对象
NSManagedObjectID