'NSObject' may not respond to -navigationController

Hi there I currently I have a warning on a line of code where I am trying to push a new view onto the screen. Outline // my NSObject receives a code=1 from my server I have set up. Everything works fine the code comes through which then initializes an AlertView where I have set up an if statement to catch the button click of my AlertView message. When that button is pressed my application falls over.

I have declared my ViewController of the view I am trying to push in its header file and there are no errors just the warning when compiled.

this is my NSObject I have made

    /////.h
    #import <Foundation/Foundation.h>


@interface alerts : NSObject {

}

- (void)pleaseRegisterDevice;

@end


/////.m
#import "alerts.h"
#import "instaCode1_3AppDelegate.h"
#import "RegisterDeviceViewController.h"


@implementation alerts

//use this alert when phone falls out of sync
- (void)pleaseRegisterDevice {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Please Register Device"
                                                    message:@"click OK to register"
                                                   delegate:sel开发者_Go百科f
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];

    [alert autorelease];
    [alert show];

}


//Catch pleaseRegisterDevice method
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
    NSString *buttonTitle=[alertView buttonTitleAtIndex:buttonIndex];
    if ([buttonTitle isEqualToString:@"OK"]) {
        NSLog(@"msg from alertView method");

        //open new wndow

        RegisterDeviceViewController *regViewController = [[RegisterDeviceViewController alloc] init];


        //Push it onto the top pf the navigation controller's stack
        **[[self navigationController] pushViewController:regViewController animated:YES];**



    }
    else {
        NSLog(@"was not able to push view");
    }

}

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

I have bolded the line of code where I get the warning 'alerts' may not respond to -navigationController

any help would be greatly appreciated.

I dont think an NSObject subclass has a UINavigationController... You need to get a pointer to your app delegate's navigation controller like so

MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.navigationController pushViewController:regViewController animated:YES];

navigationController is a property defined on a UIViewController. A NSObject does not have this method.

You don't have any instance member or method called navigationController, hence the warning.