ios / objective-c：核心数据保存错误

Question

I am trying to save an object created from some JSON in core data and it is not saving. I suspect the problem is that I am creating the managed object context too many times or trying to save to the wrong managed object context. I have to keep declaring it as I was getting managedobjectcontext = nil errors. Wondering if anyone could help me spot bug which has eluded me.

-(void) importItems:(NSArray *)ItemsToImport
{
    int i;
    int max = [itemsToImport count];
    IDItemServer *importItem;//this is import object
    Items *Item; //this is core data entity

    NSManagedObjectContext *context = self.managedObjectContext;
    for (i=0;i<max;i++)
    {
        NSLog(@"value of i is%d:",i);
        importItem = ItemsToImport[i];

            NSString *name = importItem.name;
            NSString *sub = importItem.sub;
     //save our new and updated changes to the Core Data store
            NSManagedObjectContext *context = [IDModel sharedInstance].managedObjectContext;

            NSEntityDescription *entity = [NSEntityDescription entityForName:@"Item" inManagedObjectContext:context];
        //was self.managedObjectContext
        // Initialize Record
        NSManagedObject *record = [[NSManagedObject alloc] initWithEntity:entity insertIntoManagedObjectContext:context];

            // Populate Record
         [record setValue:name forKey:@“name”];
         [record setValue:sub forKey:@“s”ub];

        }
            // Save Record
        NSError *error = nil;
        NSLog(@"BEFORE SAVE”);//Logs to console
        if ([context save:&error]) {
            NSLog(@"AFTER SAVE”);//does not log to console


        } else {
        if (error) {

        NSLog(@"%@, %@", error, error.localizedDescription);//does not log to console
        }

        // Show Alert View
        [[[UIAlertView alloc] initWithTitle:@"Warning" message:@"Your Item could not be saved." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
//THIS ALERT FIRES
        }

}

Answer 1

There was indeed an unnecessary context here. The one on line 8 should be deleted. Also check that whenever you invoke or use a MOC you are using a consistent name ie "* context" vs. "* managedobjectcontext"