非法企图建立关系

Question

我得到了这个令人讨厌的崩溃和错误.

此代码运行时发生崩溃:

    Address *address = [[Address alloc] initWithEntity:[NSEntityDescription entityForName:@"Address" inManagedObjectContext:managedObjectContext] insertIntoManagedObjectContext:nil];

        //Crashes here!
        [person addAddressObject:address];

Illegal attempt to establish a relationship 'person' between objects in different contexts

整个控制台错误如下.

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Illegal attempt to establish a relationship 'person' between objects in different contexts (source = <Address: 0x1f87e270> (entity: Address; id: 0x1f87e2b0 <x-coredata:///Address/t748EE284-0311-4489-9654-1D902EB0D4CC2> ; data: {
    addressLine1 = "";
    addressLine2 = "";
    addressLine3 = "";
    city = "";
    country = "";
    person = nil;
    state = "";
    title = "";
    zip = "";
}) , destination = <Person: 0x1ed9e1e0> (entity: Person; id: 0x1ed9c710 <x-coredata://ED0283A9-A847-407E-BFEC-CF2BF85C6A9C/Person/p1> ; data: {
    address =     (
        "0x1f87e2b0 <x-coredata:///Address/t748EE284-0311-4489-9654-1D902EB0D4CC2>",
        "0x1ed93e70 <x-coredata://ED0283A9-A847-407E-BFEC-CF2BF85C6A9C/Address/p1>"
    );
    favourite = nil;
    firstName = Josh;
    lastName = Kahane;
}))'

我不知道如何解决这个问题.据推测它认为有两种不同的managedObjectContexts？但是,在我的应用程序中,我只引用了我的app委托中所做的那样(在viewDidLoad上运行):

if (managedObjectContext == nil)
    {
        managedObjectContext = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
        NSLog(@"After managedObjectContext: %@",  managedObjectContext);
    }

关于从哪里开始寻找差异的任何想法？谢谢.

编辑:

新发现.就在应用程序崩溃之前,我已经NSLogged地址和人员管理对象上下文.结果是地址上下文(null),即使我在前面运行检查设置上下文,如果它的nil.

Answer 1

你把它插入零managedObjectContext.

您需要将对象插入到NSManagedObjectContext用于实体的对象中.即managedObjectContext.

在Address对象的alloc init中.

在OP中阅读您的评论.

你要么......

保存所有必需的值,然后在确认时创建Address对象并将其全部插入.

要么...

创建对象并插入它创建所有关系,然后如果用户按下取消,则删除该对象.

我会做这两个中的一个来避免这个错误.