Question

In my function - (void)viewDidLoad:

FirstViewController *first = [[FirstViewController alloc]init];
    SecondViewController *second = [[SecondViewController alloc]init];
    ThirdViewController *third = [[ThirdViewController alloc]init];
    ForthViewController *forth = [[ForthViewController alloc]init];
    FifthViewController *fifth = [[FifthViewController alloc]init];

    first.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"first" image:[UIImage imageNamed:@"FirstTab.png"] tag:0];
    second.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"second" image:[UIImage imageNamed:@"SecondTab.png"] tag:1];
    third.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"third" image:[UIImage imageNamed:@"ThirdTab.png"] tag:2];
    forth.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"forth" image:[UIImage imageNamed:@"ForthTab.png"] tag:3];
    fifth.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"fifth" image:[UIImage imageNamed:@"FifthTab.png"] tag:3];

UINavigationController *navigationFirst = [[UINavigationController alloc]initWithRootViewController:first];
UINavigationController *navigationSecond = [[UINavigationController alloc]initWithRootViewController:second];
UINavigationController *navigationThird = [[UINavigationController alloc]initWithRootViewController:third];
UINavigationController *navigationForth = [[UINavigationController alloc]initWithRootViewController:forth];
UINavigationController *navigationFifth = [[UINavigationController alloc]initWithRootViewController:fifth];

//    [first release];
//    [second release];
//    [third release];
//    [forth release];
//    [first release];

NSMutableArray *array = [[NSMutableArray alloc]initWithObjects:navigationFirst,navigationSecond,navigationThird,navigationForth,navigationFifth, nil];

[navigationFirst release];
[navigationSecond release];
[navigationThird release];
[navigationForth release];
[navigationFifth release];

self.tabbarController = [[UITabBarController alloc]init];
self.tabbarController.view.frame = CGRectMake(0, 0, 320, 480);
self.tabbarController.viewControllers = array;
[array release];

I intend to add five UINavigationControllers to tabcontroller,if I don’t comment the fellowing code,it will crash:

//    [first release];
//    [second release];
//    [third release];
//    [forth release];
//    [first release];

but I want to know what’s the problem,I think it is correct to add thees code.

Answer 1

you are releasing first object twice. thats why your code is crashing.
replace [first release] with [fifth release]