Question

If I use this code, the app works:

if ([self.navigationController respondsToSelector:@selector(showUpdateRecordModalWithFrontWord:andBackWord:)]) {
        NSLog(@"seems to respond");
        [self.navigationController performSelector:@selector(showUpdateRecordModalWithFrontWord:andBackWord:) 
                withObject:[currentCard frontWord] withObject:[currentCard backWord]];


    }

If I add a third parameter (below), I get a SIGABRT.

if ([self.navigationController respondsToSelector:@selector(showUpdateRecordModalWithFrontWord:andBackWord:andNotes:)]) {
        NSLog(@"seems to respond");
        [self.navigationController performSelector:@selector(showUpdateRecordModalWithFrontWord:andBackWord:andNotes:) 
                                        withObject:[currentCard frontWord] withObject:[currentCard backWord] withObject:[currentCard notes]];
    }

The method is here:

- (id)showUpdateRecordModalWithFrontWord:(NSString *)arg_name1 andBackWord:(NSString *)arg_name2 andNotes:(NSString *)arg_name3 {
    NSLog(@"%s", __FUNCTION__);

    AppProductModalController *modal = [[AppProductModalController alloc] initWithNibName:nil bundle:nil];
    [modal setNewRecord: NO];
    [modal setDelegate: self.topViewController];
    [modal.navBar.topItem setTitle: @"Update Card"];
    [modal.frontWordField setText: arg_name1];
    [modal.backWordField setText: arg_name2];
    [modal.notesField setText: arg_name3];
    [self presentModalViewController:modal animated:YES];
    [modal release];
    return nil;
}

Am I running into a limit of parameters, or am I just doing something wrong?

I appreciate any help..

Answer 1

NSObject only defines performSelector:, performSelector:withObject: and performSelector:withObject:withObject:. There’s no magic behind the scenes here where you’re “adding objects” — there just isn’t such a method as performSelector:withObject:withObject:withObject:. Probably your best solution is to just send the message directly rather than going through performSelector:. The selector doesn’t vary, so it shouldn’t be a problem.