example of auto rotate

gistfile1.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
	self.viewController = [[SO2ViewController alloc] initWithNibName:@"SO2ViewController" bundle:nil];
	self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}

@interface SO2TabViewController : UITabBarController

@end

@implementation SO2TabViewController

- (BOOL)shouldAutorotate
{
	return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
	return UIInterfaceOrientationMaskAll;
}

@end


@implementation SO2ViewController

- (BOOL)shouldAutorotate
{
	return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
	return UIInterfaceOrientationMaskAllButUpsideDown;
}

- (IBAction)showTabBar:(UIButton *)sender
{
	SO2ViewController *v1 = [[SO2ViewController alloc] init];
	SO2ViewController *v2 = [[SO2ViewController alloc] init];
	SO2TabViewController *tab = [[SO2TabViewController alloc] init];
	tab.viewControllers = @[v1, v2];
	[self presentViewController:tab animated:YES completion:nil];
}
@end