iPhone开发 使用tabbarcontroller

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    
    //生成各个视图控制器
    MedicalData* aa = [[MedicalData alloc]init];
    HealthRecord* bb = [[HealthRecord alloc]init];
    KonwledgeBase* cc = [[KonwledgeBase alloc]init];
    CarePrescription* dd = [[CarePrescription alloc]init];
    //加入一个数组    
    NSArray* controllerArray = [[NSArray alloc]initWithObjects:aa,bb,cc,dd ,nil];
    //创建UITabBarController控制器  (定义在.h中，否在开启arc会自动释放掉，内存访问出错)
    tabBarController = [[UITabBarController alloc]init];
    //设置委托
    tabBarController.delegate = self;
    //设置UITabBarController控制器的viewControllers属性为我们之前生成的数组controllerArray
    tabBarController.viewControllers = controllerArray;
    //默认选择第1个视图选项卡（索引从0开始的）
    tabBarController.selectedIndex = 0;
    //设置TabBarItem的标题与图片
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:0] setTitle:@"aa"];  
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:0] setImage:[UIImage imageNamed:@"1517.png"]];  //30 * 30
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:1] setTitle:@"bb"];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:1] setImage:[UIImage imageNamed:@"light.png"]];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:2] setTitle:@"cc"];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:2] setImage:[UIImage imageNamed:@"podcaste.png"]];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:3] setTitle:@"dd"];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:3] setImage:[UIImage imageNamed:@"setting.png"]];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:4] setTitle:@"ee"];
    [(UITabBarItem *)[tabBarController.tabBar.items objectAtIndex:4] setImage:[UIImage imageNamed:@"unlock.png"]];
    //读取
    UIViewController* activeController = tabBarController.selectedViewController;
    if(activeController == aa){
        //
    }
    //把tabBarController的view作为子视图添加到window
    [self.window addSubview:tabBarController.view];
    [self.window makeKeyAndVisible];
    return YES;

}