核心数据 - 神奇记录 - 创建实体,更新并保存它

Question

我真的不明白为什么这给了我这么多麻烦.我正在使用Magical Record的核心数据包装器来创建实体,更新并保存它们.我能够完美地创建和获取实体,很好.创建的实体很好地被保留,但是,我无法对实体进行更改,并且一旦应用程序终止,这些更改就会持续存在.这是我如何设置魔法记录.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [MagicalRecord setupCoreDataStack];

    return YES;
}

我的应用程序终止时

- (void)applicationWillTerminate:(UIApplication *)application {

    [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];
    [MagicalRecord cleanUp];
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    // Saves changes in the application's managed object context before the application terminates.
}

我如何创建我的实体

   //Create a new payment entity and save it to the persistant data store, dismiss view controller upon saving
        PaymentEntity *newPaymentEntity = [PaymentEntity MR_createEntity];
        newPaymentEntity.title = self.titleTextField.text;
        newPaymentEntity.paymentAmount = self.amountOwedTextField.text;
        newPaymentEntity.notes = self.notesTextView.text;
        newPaymentEntity.debtors = self.debtorsArray;
        newPaymentEntity.createdAt = [NSDate date];
        newPaymentEntity.isPayed = NO;
        if (self.setDueDateSwitch.on)
            newPaymentEntity.dueDate = self.dueDate;
        else
            newPaymentEntity.dueDate = nil;

        [newPaymentEntity.managedObjectContext MR_saveToPersistentStoreWithCompletion:^(BOOL contextDidSave, NSError *error) {
            if (error) {
                NSLog(@"%@", error.description);
            }
            else{
                [self dismissViewControllerAnimated:YES completion:nil];
            }
        }];

以及我如何尝试将更改保存到我的实体.

-(void)viewWillDisappear:(BOOL)animated
{
    [MagicalRecord saveWithBlock:^(NSManagedObjectContext *localContext) {

        PaymentEntity *payment = [self.payment MR_inContext:localContext];
        payment.amountPayed = self.amountPayedLabel.text;
        payment.debtors = self.debtorsArray;

        [localContext MR_saveToPersistentStoreAndWait];
    }];
    [super viewWillDisappear:animated];
}

知道我做错了什么吗？就像我说的,一旦我创建了一个实体,它就会持续存在,但是一旦应用程序终止,我对实体所做的所有更改都不会持续存在.