Navigating back from custom UISplitview - ios

Question

In my iPad application, i have a main menu screen.. with various icons on it.
On tapping on an icon, it navigates me to Custom UISplitViewController. I did it with this code. Everything is working fine in SplitView.
Problem: I am facing issue to get back to my Main Menu screen on tapping a button in MASTER Viewcontroller's Navigation bar.
code for Custom UIsplitview:-
self.navigationController.navigationBarHidden = NO;
self.navigationController.navigationBar.barStyle = UIBarStyleBlack;
left = [[LeftViewController alloc] initWithStyle:UITableViewStylePlain];
UINavigationController *leftNav = [[UINavigationController alloc] initWithRootViewController:left];
right = [[RightViewController alloc] initWithNibName:#"RightViewController" bundle:nil];
UINavigationController *rightNav = [[UINavigationController alloc] initWithRootViewController:right];
left.right = right;
splitViewController = [[UISplitViewController alloc] init];
splitViewController.viewControllers = [NSArray arrayWithObjects:leftNav,rightNav, nil];
splitViewController.delegate = right;
appDelegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];
UISplitViewController *cvc = (UISplitViewController *) splitViewController;
[appDelegate.window setRootViewController:cvc];
EDIT: Custom button code
UIButton *a1 = [UIButton buttonWithType:UIButtonTypeCustom];
[a1 setFrame:CGRectMake(0.0f, 0.0f, 32.0f, 32.0f)];
[a1 addTarget:self action:#selector(menu:) forControlEvents:UIControlEventTouchUpInside];
[a1 setImage:[UIImage imageNamed:#"icon.png"] forState:UIControlStateNormal];
UIBarButtonItem *random = [[UIBarButtonItem alloc] initWithCustomView:a1];
left.navigationItem.leftBarButtonItem = random;
- (void)menu {
[self.view removeFromSuperview];
ViewController *vc = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
[appDelegate.window setRootViewController:vc];
[vc release];
}
This causes CRASH, with EXC_BAD_ACCESS message.
Pls guide me..

Answer 1

I assume you can see which line of your code the crash happens on by stepping through from a breakpoint?
I'm not a fan of your sw design here to be honest as I wouldn't use a UISplitViewController subclass. I'd be more likely to create a custom SplitViewController using UIViewController containment APIs and then use that in conjunction with a UINavigationController.
That said, if you must use a UISplitViewController subclass then I would suggest having all your code to add or remove the viewControllers from the window in the main appDelegate and then use notifications to tell the appDelegate when to add or remove the relevant viewControllers (switch the root). This way you reduce the potential to have multiple instances of the same view controllers hanging around leading memory issues. It's always tricky to try to get a viewController to remove itself from it's parent, and is best managed by parent or higher level entity (in this case the main app delegate).

Answer 2

I'm not sure this is a good design. What else do you do from your main menu screen bedsides going to the split view controller?
If you want to keep this design, you would do the same thing you did at the end of your posted code -- in the button's action method, create an instance of your main menu controller and set it as the window's root view controller.
After Edit:
I can see one problem that's sure to create a crash -- when you create your button, you have the action set as "menu:", but your method implementation is just "menu" with no colon or arguments. Remove the colon, and everything should work.
I don't think these 3 lines are causing trouble, but there's no need to do what you're doing:
appDelegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];
UISplitViewController *cvc = (UISplitViewController *) splitViewController;
[appDelegate.window setRootViewController:cvc];
You already have a property or ivar, splitViewController, there's no need to reassign it to cvc. Also there's no need to get the app delegate, you can get the window with self.view.window. So those 3 line can be changed to just this:
self.view.window.rootViewController = splitViewController;