PushViewController: Is this a memory leak? - iphone

Question

I'm developing an iOS 4 with latest SDK and XCode 4.2 (I'm not using ARC).
I'm developing a Navigation Controller programmatically, and I have a question.
This is AppDelegate.h
#import <UIKit/UIKit.h>
#class ViewController;
#class SecondViewController;
#interface AppDelegate : UIResponder <UIApplicationDelegate>
{
UINavigationController* navController;
ViewController* viewController;
SecondViewController* secondViewController;
}
#property (strong, nonatomic) UIWindow *window;
- (void) showSecondViewController;
#end
And this is AppDelegate.m
#import "AppDelegate.h"
#import "ViewController.h"
#import "SecondViewController.h"
#implementation AppDelegate
#synthesize window = _window;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
viewController.title = #"Menu";
navController = [[UINavigationController alloc] initWithRootViewController:viewController];
navController.navigationBar.tintColor = [UIColor blackColor];
self.window.rootViewController = navController;
[self.window makeKeyAndVisible];
return YES;
}
- (void) dealloc
{
[_window release];
[viewController release];
[navController release];
[secondViewController release];
}
- (void)applicationWillResignActive:(UIApplication *)application
{
...
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
...
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
...
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
...
}
- (void)applicationWillTerminate:(UIApplication *)application
{
...
}
- (void) showSecondViewController
{
secondViewController = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
secondViewController.title = #"Second";
[navController pushViewController:secondViewController animated:YES];
}
My question is about the last method, -(void)showSecondViewController;
May I add this line at the end?
[secondViewController release]
I've profiled the application, and I haven't see any memory leaks. But I have to ask it here, because I'm not sure.

Answer 1

You will get a memory leak if you call showSecondViewController method again.
You should release the secondViewController in your showSecondViewController method.
- (void) showSecondViewController
{
secondViewController = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
secondViewController.title = #"Second";
[navController pushViewController:secondViewController animated:YES];
[secondViewController release]
}
It will automatically be retained by navController when you do pushViewController:secondViewController