MagicalRecord — saveinBackground not persisting data?

问题

I'm having trouble understanding the difference betweeen [[NSManagedObjectContext defaultContext] save] and [[NSManagedObjectContext defaultContext] saveInBackground].

When I use the save functionality, it works just fine but saveInBackground never persists the data. In short, this is the difference:

// Save in background.. DOES NOT WORK
    [[NSManagedObjectContext defaultContext] saveInBackgroundErrorHandler:^(NSError *error){
        NSLog(@"FAILED TO SAVE!! Task: %@", task);
    }completion:^(void){
        NSLog(@"PERSISTED NEW TASK: %@", task);
    }];

    // Save in main thread.. WORKS
    [[NSManagedObjectContext defaultContext] save];

Everytime saveInBackground runs, I see the "PERSISTED NEW TASK" log entry. However, when I restart the app, the data isn't there. When I use save, I restart the app and the data is there. What am I missing?

回答1:

Had to call [context saveNestedContexts]

来源：https://stackoverflow.com/questions/12410213/magicalrecord-saveinbackground-not-persisting-data