Question

While going through a tutorial which uses a navigation based- application, I decided to create a Navigation-Based Application with my 3.2.6-Xcode and open it with Xcode 4.2 for following the tutorial with that version.
But when I open the same project in Xcode 4.2 (without changing or adding any code), the 4.2 Xcode gives me 2 errors saying:

RootViewController cannot use ‘super’ because it is a root class

Right now, my Xcode has 4 class-files: RootViewController.h, RootViewController.m, SaveUpAppDelegate.h and SaveUpAppDelegate.m. The error is in RootViewController.m:

- (void)dealloc {
    [super dealloc];
}

and

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Relinquish ownership any cached data, images, etc that aren't in use.
}

I already searched through the internet and found this discussion (http://stackoverflow.com/questions/10113669/xcode-4-3-2-gives-error-cannot-use-super-because-it-is-a-root-class) and they say that the reason might be that the controller is that the developer forgot the superclass in the @interface line. That doesn’t fit to my case, because I (or better: Xcode 3.2.6) didn’t forget the superclass in RootViewController.h…

#import <UIKit/UIKit.h>

@interface RootViewController : UITableViewController {
}

@end

right now, I commented those critical lines out and it works fine, but I’m sure, I’ll need those lines since most of the automatic created lines in the m-file are done with [super ….].

How to solve the problem?

Answer 1

Clean. It’s an option under “Run”. It removes all the build files that are automatically generated.