iphone - 如何为子类化的 NSManagedObject 正确实现自定义初始化程序

Question

我想知道创建自己的类初始化器的正确方法是什么，该类是 NSManagedObject 的子类。

目前我正在这样初始化:

-(id)initWithXML:(TBXMLElement *)videoXML
{
    // Setup the environment for dealing with Core Data and managed objects
    HenryHubAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
    NSManagedObjectContext *context = [appDelegate managedObjectContext];
    NSEntityDescription *entityHubPieceVideo = [NSEntityDescription entityForName:@"HubPieceVideo" 
                                                           inManagedObjectContext:context];

    self = [[HubPieceVideo alloc] initWithEntity:entityHubPieceVideo insertIntoManagedObjectContext:context];
    // do stuff and then save

    NSError *error;
    if(![context save:&error]) 
    {
        NSLog(@"HubPiece video save context error: %@ %@", error, [error userInfo]); 
    }
}

好像some其他 also这样做。

Answer 1

刚发现NSManagedObject reference说:

If you instantiate a managed object directly, you must call the designated initializer (initWithEntity:insertIntoManagedObjectContext:).