Have to apply tabbar for single view application

Question

Iam using xcode4.2 i added 3 items for tabbar in singe view application .

The problem is i cant visualize the output instead of a black screen is shown on ios simulator

Can anyone help me please

my code is

@synthesize window = _window;
@synthesize viewController = _viewController;
@synthesize appNavigation = _appNavigation;  

- (void)dealloc
{
    [_window release];
    [_viewController release];
    [_appNavigation release];    
    [super dealloc];
}



- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
        self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];

            UITabBarController *tabController = [[UITabBarController alloc] init];
            NSMutableArray *tabsArray = [[NSMutableArray alloc] init];
            `enter code here`ViewController *homeScreen = [[ViewController alloc] init];
            homeScreen.navigationItem.title = @"App Title";
            _appNavigation = [[UINavigationController alloc]initWithRootViewController:homeScreen];
            _appNavigation.tabBarItem.title = @"Home";
            [_appNavigation.tabBarItem setImage:[UIImage imageNamed:@"Home_Button.png"]];
            [tabsArray addObject:_appNavigation];
            [_appNavigation release];

            BookmarksViewController *bookMark = [[BookmarksViewController alloc] init];
            bookMark.navigationItem.title = @"Bookmarks";
            _appNavigation = [[UINavigationController alloc] initWithRootViewController:bookMark];
            [_appNavigation.tabBarItem initWithTabBarSystemItem:UITabBarSystemItemBookmarks tag:2];
            _appNavigation.tabBarItem.title = @"Bookmarks";
            [tabsArray addObject:_appNavigation];
            [_appNavigation release];

            AppSettingsController *settings = [[AppSettingsController alloc] initWithStyle:UITableViewStyleGrouped];
            settings.navigationItem.title = @"Settings";
            _appNavigation = [[UINavigationController alloc] initWithRootViewController:settings];
            _appNavigation.tabBarItem.title = @"Settings";
            [_appNavigation.tabBarItem setImage:[UIImage imageNamed:@"Settings_Button.png"]];
            [tabsArray addObject:_appNavigation];
            [_appNavigation release];

            SearchViewController *searchView = [[SearchViewController alloc] init];
            searchView.navigationItem.title = @"Ranga";
            _appNavigation = [[UINavigationController alloc] initWithRootViewController:searchView];
            _appNavigation.tabBarItem.title = @"Search";
            [_appNavigation.tabBarItem initWithTabBarSystemItem:UITabBarSystemItemSearch tag:4];
            [tabsArray addObject:_appNavigation];
            [_appNavigation release];


            tabController.viewControllers = tabsArray;


LoginViewController *loginView = [[LoginViewController alloc] init];

           [self.window addSubview:tabController.view];

[tabController presentModalViewController:loginView animated:NO];

    [self.window makeKeyAndVisible];
    return YES;
}


@end

Answer 1

Just update your application code this way.

1. change in code

open AppDelegate.h file it should be like

#import <UIKit/UIKit.h>

@class FirstViewController,SecondViewController;


@interface AppDelegate : UIResponder <UIApplicationDelegate, UITabBarControllerDelegate>


@property (strong, nonatomic) UIWindow *window;

//these two view controllers (screens) for adding to tabs.
@property (strong, nonatomic) FirstViewController *firstViewController;
@property (strong, nonatomic) SecondViewController *secondViewController;

//this will be the tab bar-controller
@property (strong, nonatomic) UITabBarController *baseTabBarController;

@end

now your AppDelegate.m file code should be like

#import "AppDelegate.h"    
#import "FirstViewController .h"
#import "SecondViewController.h"


@implementation AppDelegate

@synthesize window = _window;
@synthesize firstViewController;
@synthesize secondViewController;
@synthesize baseTabBarController;



- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 

    // create tab bar
    baseTabBarController = [[UITabBarController alloc]init];

    baseTabBarController.delegate=self;

    // initialize first screen
    firstViewController = [[FirstViewController alloc] initWithNibName:@"FirstViewController " bundle:nil]; 
    UINavigationController *homeView = [[UINavigationController alloc]initWithRootViewController:firstViewController]; 
    firstViewController.title = @"Home ";

    // initialize second screen
    secondViewController = [[SecondViewController alloc] initWithNibName:@"FavViewController" bundle:nil];
    secondViewController.title = @"My Favourite";
    UINavigationController *favouriteView = [[UINavigationController alloc] initWithRootViewController:secondViewController];  

    //add both views in array
    NSArray *controllers = [NSArray arrayWithObjects:homeView,favouriteView, nil];
    //add array to tab bar  
    baseTabBarController.viewControllers = controllers; 
    //add tab bar to window
    self.window.rootViewController = baseTabBarController;


    [self.window makeKeyAndVisible];    

    return YES;
}

2. in UI change

now go to xib file for both view controller what we want to add TAB, just change this way in Interface builder

Bottom Bar = Tab Bar

that's it!! you will get two tab at the bottom of your application.

Feel free to ask me if you have any question.