在viewDidLoad里写tabbar

UITabBarController* tabbar = [[UITabBarController alloc] init];

tabbar.delegate = self;

FirstViewController* first = [[FirstViewController alloc] init];

SecondViewController* second = [[SecondViewController alloc] init];

NSArray* array = [NSArray arrayWithObjects:first,second, nil];

tabbar.viewControllers = array;

[first.tabBarItem initWithTitle:@"first" image:[UIImage imageNamed:@"alarm_30.png"] tag:1];

[second.tabBarItem initWithTitle:@"second" image:[UIImage imageNamed:@"alien_30.png"] tag:2];

first.tabBarItem.badgeValue = @"1";

[self.view addSubview:tabbar.view];