Question

- (void)cancel {
// What should I do here?
}

// root view controller
- (void)viewDidLoad {
    [super viewDidLoad];

    UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(cancel)];
    self.navigationItem.leftBarButtonItem = cancelButton;
    [cancelButton release];     
}

I added cancel button in the navigation bar.
I want to go back to the previous view from root view when cancel button is pressed.
What do I have to do in cancel? I added root view controller like this.

RootController *rootController = [[RootController alloc]initWithStyle:UITableViewStylePlain];               
UINavigationController *aNavigationController = [[UINavigationController alloc]initWithRootViewController:rootController];
self.naviController = aNavigationController;
[aNavigationController release];
[rootController release];
[self.view addSubview:[naviController view]];

Answer 1

You can pop the view.

[self.navigationController popViewControllerAnimated:YES];

You can dismiss it as well.

dismissModalViewcontrollerAnimated

EDIT:
If you are adding the view then you need to remove your view.

[self.view removeFromSuperView];