I am trying to implement Tabs into my secondView.On button touch(from ViewController.m) I am navigating to secondView(Tabs). In my Tabs.xib file I have added a TabBar at bottom and it is custom class of UITabBar.
ViewController.m
- (IBAction)touchedInside:(id)sender {
NSLog(#"touhced up inside");
Tabs *temp = [[Tabs alloc]initWithNibName:#"Tabs" bundle:nil];
[self.navigationController pushViewController:temp animated:YES];
[self presentViewController:temp animated:YES completion:nil];
}
Tabs.m
- (void)viewDidLoad
{
[super viewDidLoad];
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
UITabBarController *tabBarController = [[UITabBarController alloc]init];
/*
Tab_1 *firstView = [[Tab_1 alloc] init];
UITabBarItem *item1 = [[UITabBarItem alloc]initWithTitle:#"First" image:nil tag:1];
[firstView setTabBarItem:item1];
NSLog(#"after first tab is added");
Tab_2 *secondView = [[Tab_2 alloc] init];
UITabBarItem *item2 = [[UITabBarItem alloc]initWithTitle:#"Sec" image:nil tag:1] ;
[secondView setTabBarItem:item2];
NSLog(#"after second tab is added");
[tabBarController setViewControllers:[NSArray arrayWithObjects:firstView,secondView,nil] animated:NO];
NSLog(#"after tab is added");
[appDelegate.window addSubview:tabBarController.view];
NSLog(#"after view is added");
*/
appDelegate.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
UIViewController *viewController1 = [[Tab_1 alloc] initWithNibName:#"Tab 1" bundle:nil];
UIViewController *viewController2 = [[Tab_2 alloc] initWithNibName:#"Tab 2" bundle:nil];
UIViewController *viewController3 = [[Tab_2 alloc] initWithNibName:#"Tab 1" bundle:nil];
tabBarController.viewControllers = [NSArray arrayWithObjects:viewController1, viewController2, viewController3, nil];
appDelegate.window.rootViewController = self.tabBarController;
[appDelegate.window makeKeyAndVisible];
Tabs *temp = [[Tabs alloc]initWithNibName:#"Tabs" bundle:nil];
[self.navigationController presentModalViewController:temp animated:NO];
}
Errors
Unbalanced calls to begin/end appearance transitions for <ViewController: 0x6833c80>.
2012-12-06 09:57:48.963 demoTabs[667:f803] Unbalanced calls to begin/end appearance transitions for <Tabs: 0x6a3fc90>.
Tab_1 *viewController1 = [[Tab_1 alloc] initWithNibName:#"Tab 1" bundle:nil];
Tab_2 *viewController2 = [[Tab_2 alloc] initWithNibName:#"Tab 2" bundle:nil];
Tab_2 *viewController3 = [[Tab_2 alloc] initWithNibName:#"Tab 1" bundle:nil];
Define the instance of viewcontroller as above defined, also make sure to give coorect nib file name against each viewcontroller.
Related
this view present 5 buttons(sorry is in french)
i want to implement a tabbarcontroller when i choose one button , it will navigate to the tabbarControllerClass my problem that i don't know how to program action in every buttton to push to this view
this is an example of mesAlertbuttonpressed
-(IBAction)MesAlertsButtonPressed:(id)sender{
TabBarControllerViewController *tabBarControllerViewController = [[TabBarControllerViewController alloc]initWithNibName:#"TabBarControllerViewController" bundle:nil];
tabBarControllerViewController.TypeView=#"Alert";
[self.navigationController pushViewController:tabBarControllerViewController animated:YES];
Create method in AppDelegate.m class and call that method when you want to display tabController For Example:
-(void)setRootViewControllerTab1{
UIViewController *viewController1, *viewController2, *viewController3, *viewController4, *viewController5;
UINavigationController *navviewController1 , *navviewController2, *navviewController3, *navviewController4, *navviewController5;
viewController1 = [[[HomeViewController alloc] initWithNibName:#"HomeViewController" bundle:nil] autorelease];
navviewController1=[[UINavigationController alloc]initWithRootViewController:viewController1];
viewController2 = [[[HowItWorksViewController alloc] initWithNibName:#"HowItWorksViewController" bundle:nil] autorelease];
navviewController2=[[UINavigationController alloc]initWithRootViewController:viewController2];
viewController3 = [[[JoiniAppointViewController alloc] initWithNibName:#"JoiniAppointViewController" bundle:nil] autorelease];
navviewController3=[[UINavigationController alloc]initWithRootViewController:viewController3];
viewController4 = [[[BecomeBussUserViewController alloc] initWithNibName:#"BecomeBussUserViewController" bundle:nil] autorelease];
navviewController4=[[UINavigationController alloc]initWithRootViewController:viewController4];
viewController5 = [[[ContactUsViewController alloc] initWithNibName:#"ContactUsViewController" bundle:nil] autorelease];
navviewController5=[[UINavigationController alloc]initWithRootViewController:viewController5];
self.tabBarController.viewControllers = [NSArray arrayWithObjects:navviewController1, navviewController2,navviewController3,navviewController4,navviewController5, nil];
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
}
and call that method on that button click event like bellow..
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate setRootViewControllerTab1];
Use this line of code to call a method to create tab bar-
AppDelegate *appDelegateObj = (AppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegateObj createTabBar];
Actual Method
-(void)createTabBar
{
self.tabBarController.customizableViewControllers = nil;
Home *homeObj = [[Home alloc] initWithNibName:#"Home" bundle:nil];
UINavigationController *tab1Controller = [[UINavigationController alloc] initWithRootViewController:homeObj];
ChatList *chatListObj = [[ChatList alloc] initWithNibName:#"ChatList" bundle:nil];
UINavigationController *tab2Controller = [[UINavigationController alloc] initWithRootViewController:chatListObj];
Settings *settingObj = [[Settings alloc] initWithNibName:#"Settings" bundle:nil];
UINavigationController *tab3Controller = [[UINavigationController alloc] initWithRootViewController:settingObj];
self.tabBarController.viewControllers = [NSArray arrayWithObjects: tab1Controller, tab2Controller,tab3Controller, nil];
self.tabBarController.selectedIndex=0;
self.tabBarController.delegate = self;
self.window.backgroundColor=[UIColor clearColor];
self.tabBarController.view.backgroundColor=[UIColor clearColor];
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
}
I'm not shure if i understand you right.
Is you view already conrolled by an view controller? If not, then your action will not work.
you can try to show it modal:
-(IBAction)MesAlertsButtonPressed:(id)sender
{
TabBarControllerViewController *tabBarControllerViewController = [[TabBarControllerViewController alloc]initWithNibName:#"TabBarControllerViewController" bundle:nil];
tabBarControllerViewController.TypeView=#"Alert";
[self presentModalViewController:tabBarControllerViewController animated:YES];
}
otherwise you should read the docs about UINavigationController.
I have an activation page in my app, which is mandatory for every user to activate the app.
Once the app is activated, the user moves to the tabbed bar view.
I have created a tabbed bar application, where from my activationView on click of button I am trying to call the tab bar, I am getting an entire black screen.
- (IBAction)moveToActivateView:(id)sender {
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
UITabBarController *tabBarController = [[UITabBarController alloc]init];
[self.view addSubview:tabBarController.view];
appDelegate.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UIViewController *viewController1 = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
UIViewController *viewController2 = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
self.tabBarController.viewControllers = #[viewController1, viewController2];
appDelegate.window.rootViewController = self.tabBarController;
[appDelegate.window makeKeyAndVisible];}
Hey make your tabBarController's property in appDelegate and assign all ViewController there then call your tabBarController from yourViewController
in AppDelegate.h
#property (nonatomic, retain) IBOutlet UINavigationController *navigationController;
#property (retain, nonatomic) IBOutlet UITabBarController *tabBarController;
in AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self makeTabBar];
[self addInitialVIew];
[self.window makeKeyAndVisible];
return YES;
}
-(void)makeTabBar
{
tabBarController = [[UITabBarController alloc] init];
tabBarController.delegate=self;
FirstViewController *firstVC =[[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
UINavigationController *firstNC = [[UINavigationController alloc] initWithRootViewController:firstVC];
firstNC.tabBarItem.title=#"Profile";
firstVC.tabBarController.tabBar.tag = 0;
SecondViewController *secondVC = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
UINavigationController *SecondNavController = [[UINavigationController alloc] initWithRootViewController:secondVC];
SecondNavController.tabBarItem.title = #"Search";
secondVC.tabBarController.tabBar.tag = 1;
NSArray *viewControllers =[[NSArray alloc]initWithObjects:firstNC,SecondNavController, nil];
[tabBarController setViewControllers:viewControllers animated:NO];
}
-(void) addInitialVIew
{
InitialViewController *initialViewController = [[InitialViewController alloc]initWithNibName:#"InitialViewController" bundle:nil];
navigationController = [[UINavigationController alloc]initWithRootViewController:ViewController];
[self.window addSubview:navigationController.view];
}
Now in InitialViewController you can add yourTabBar and remove InitialViewController
- (IBAction)switchToTabBarBtnPress:(id)sender
{
AppDelegate *appdelegte =(AppDelegate*)[[UIApplication sharedApplication]delegate];
[[[appdelegte navigationController] view]removeFromSuperview];
[[appdelegte window]addSubview:[[appdelegte tabBarController]view]];
[[appdelegte tabBarController]setSelectedIndex:0];
}
And Follow my answer
Answer
You want to create dynamic tabbar application to resolve your problem. So you just create the view based application. in the view controller viewdidload method put these code
tabbar1 = [[UITabBarController alloc] init];
artist_tab_obj = [[artist_tab alloc] initWithNibName:#"artist_tab" bundle:nil];
UINavigationController *tabItem1 = [[[UINavigationController alloc] initWithRootViewController: artist_tab_obj] autorelease];
tabItem1.title=#"Artist";
tabItem1.tabBarItem.image=[UIImage imageNamed:#"Icon1.png"];
music_tab_obj = [[music_tab alloc] initWithNibName:#"music_tab" bundle:nil];
UINavigationController *tabItem2 = [[[UINavigationController alloc] initWithRootViewController: music_tab_obj] autorelease];
tabItem2.title=#"Music";
tabItem2.tabBarItem.image=[UIImage imageNamed:#"Icon2.png"];
shout_tab_obj = [[shout_tab alloc] initWithNibName:#"shout_tab" bundle:nil];
UINavigationController *tabItem3 = [[[UINavigationController alloc] initWithRootViewController: shout_tab_obj] autorelease];
tabItem3.title=#"Shout";
tabItem3.tabBarItem.image=[UIImage imageNamed:#"Icon3.png"];
schedule_tab_obj = [[schedule_tab alloc] initWithNibName:#"schedule_tab" bundle:nil];
UINavigationController *tabItem4 = [[[UINavigationController alloc] initWithRootViewController: schedule_tab_obj] autorelease];
tabItem4.title=#"Schedule";
tabItem4.tabBarItem.image=[UIImage imageNamed:#"Icon4.png"];
follow_tab_obj = [[follow_tab alloc] initWithNibName:#"follow_tab" bundle:nil];
UINavigationController *tabItem5 = [[[UINavigationController alloc] initWithRootViewController: follow_tab_obj] autorelease];
tabItem5.title=#"Follower";
tabItem5.tabBarItem.image=[UIImage imageNamed:#"Icon5.png"];
tabbar1.viewControllers = [NSArray arrayWithObjects:tabItem1, tabItem2,tabItem3,tabItem4,tabItem5,nil];
In user acceptation is yes button action call this code.
[self.view insertSubview:tabbar1.view belowSubview: artist_tab_obj.view];
tabbar1.selectedIndex=1;
[self presentModalViewController:tabbar1 animated:YES];
Did you realize that your local varialbe tabBarController is not identical but sort of hides the property self.tabBarController? You create a new UITabBarCotnroller and assign it to your local variable tabBarController, which is accessible from this method only. Then you manipulate (add newly created view controllers) etc to self.tabBarController. Self.tabBarController could easily be nil here or anything else. But it is not the very UITabBarController that you just created.
And it is self.tabBarController (so probably nil) what you assign to the window as rootViewController.
You do add the tabBarController's view as subview to self.view. Besides that I do not know what self acutally is, I don't think is it really nessessary to manually add the tabBar's view as subview. Setting the root view controller (properly) should be enough
The title pretty much says it all. I'm trying to create an interface where after connecting with Facebook, the window loads up my HomeViewController (my initially selected UITabBarItem). Although, I do not want the UINavigationBar that comes through as I have set the HomeViewController as the LoginViewController's root view. I have different navigation bar items for each view, so defaulting to that one won't work. I have this code now.
AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.mainViewController = [[HomeViewController alloc] initWithNibName:#"HomeViewController" bundle:nil];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:self.mainViewController];
self.window.rootViewController = self.navigationController;
}
Create your custom tabbar Class add it in appDelegate
appDelegate.m
self.tabBarVC = [[[TabBarVC alloc] init] autorelease];
self.navController = [[[UINavigationController alloc]initWithRootViewController:self.tabBarVC]autorelease];
self.window.rootViewController = self.navController;
TabBarVC.h
#import <UIKit/UIKit.h>
#interface TabBarVC : UITabBarController
#end
TabBarVC.m
#import "TabBarVC.h"
#import "ViewController1.h"
#import "ViewController2.h"
#implementation TabBarVC
- (void)viewDidLoad
{
[super viewDidLoad];
UIViewController *vc1 = [[UIViewController alloc] initWithNibName:#"ViewController1" bundle:nil];
UIViewController *vc2 = [[UIViewController alloc] initWithNibName:#"ViewController2" bundle:nil];
[self setViewControllers:[NSArray arrayWithObjects:vc1,vc2, nil]];
}
#end
After a good nights sleep, I was able to figure it out. Hopefully, this can help others out there!
AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.tabBarController = [[UITabBarController alloc] init];
// Initialize view controllers
HomeViewController *homeViewController = [[HomeViewController alloc] initWithNibName:#"HomeViewController" bundle:nil];
ConnectViewController *connectViewController = [[ConnectViewController alloc] initWithNibName:#"ConnectViewController" bundle:nil];
PartyControlViewController *partyControlViewController = [[PartyControlViewController alloc] initWithNibName:#"PartyControlViewController" bundle:nil];
MeViewController *meViewController = [[MeViewController alloc] initWithNibName:#"MeViewController" bundle:nil];
MoreViewController *moreViewController = [[MoreViewController alloc] initWithNibName:#"MoreViewController" bundle:nil];
[self.tabBarController setViewControllers:[NSArray arrayWithObjects:homeViewController, connectViewController, partyControlViewController, meViewController, moreViewController, nil]];
// Customize Tab Bar
UITabBarItem *homeTab = [[UITabBarItem alloc] initWithTitle:#"Home" image:nil tag:0];
UITabBarItem *connectTab = [[UITabBarItem alloc] initWithTitle:#"Connect" image:nil tag:1];
UITabBarItem *partyControlTab = [[UITabBarItem alloc] initWithTitle:#"Party Control" image:nil tag:2];
UITabBarItem *meTab = [[UITabBarItem alloc] initWithTitle:#"Me" image:[UIImage imageNamed:#"person.png"] tag:3];
UITabBarItem *moreTab = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemMore tag:4];
[homeViewController setTabBarItem:homeTab];
[connectViewController setTabBarItem:connectTab];
[partyControlViewController setTabBarItem:partyControlTab];
[meViewController setTabBarItem:meTab];
[moreViewController setTabBarItem:moreTab];
self.window.rootViewController = self.tabBarController;
}
According to Apple, I can combine UINavigationController and UITabBarController using the code, e.g.
MyViewController1* vc1 = [[MyViewController1 alloc] init];
MyViewController2* vc2 = [[MyViewController2 alloc] init];
MyViewController3* vc3 = [[MyViewController3 alloc] init];
MyNavRootViewController* vc4 = [[MyNavRootViewController alloc] init];
UINavigationController* navController = [[UINavigationController alloc]
initWithRootViewController:vc4];
NSArray* controllers = [NSArray arrayWithObjects:vc1, vc2, vc3, navController, nil];
tabBarController.viewControllers = controllers;
In this setup, only vc4 has the UINavigationController, but what if I want vc1-vc3 also has the UINavigationController?, should I do like..
MyViewController1* vc1 = [[MyViewController1 alloc] init];
UINavigationController* nv1 = [[UINavigationController alloc]
initWithRootViewController:vc1];
MyViewController1* vc2 = [[MyViewController2 alloc] init];
UINavigationController* nv2= [[UINavigationController alloc]
initWithRootViewController:vc2];
MyViewController1* vc3 = [[MyViewController3 alloc] init];
UINavigationController* nv3 = [[UINavigationController alloc]
initWithRootViewController:vc3];
NSArray* controllers = [NSArray arrayWithObjects:nv1, nv2, nv3, nil];
tabBarController.viewControllers = controllers;
Is this the right approach?
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
// Override point for customization after application launch.
self.tabBarController = [[[UITabBarController alloc] init] autorelease];
self.tabBarController.viewControllers = [self initializeTabBarItems];
self.navigationController = [[UINavigationController alloc]init];
[self.navigationController setNavigationBarHidden:YES];
self.window.rootViewController = self.navigationController;
[self.navigationController pushViewController:_tabBarController animated:YES];
[self.window makeKeyAndVisible];
return YES;
}
- (NSArray *)initializeTabBarItems
{
NSArray * retval;
/* Initialize view controllers */
UIViewController *viewController1 = [[[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil] autorelease];
UIViewController *viewController2 = [[[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil] autorelease];
UIViewController *viewController3 = [[[ThirdViewController alloc]initWithNibName:#"ThirdViewController" bundle:nil]autorelease];
UIViewController *viewController4 = [[[FourthViewController alloc] initWithNibName:#"FourthViewController" bundle:nil] autorelease];
UIViewController *viewController5 = [[[FivfthViewController alloc] initWithNibName:#"FivfthViewController" bundle:nil] autorelease];
/* Initialize navigation controllers */
UINavigationController * navigationController1 = [[UINavigationController alloc] initWithRootViewController:viewController1];
UINavigationController * navigationController2 = [[UINavigationController alloc] initWithRootViewController:viewController2];
UINavigationController * navigationController3 = [[UINavigationController alloc] initWithRootViewController:viewController3];
UINavigationController * navigationController4 = [[UINavigationController alloc] initWithRootViewController:viewController4];
UINavigationController * navigationController5 = [[UINavigationController alloc] initWithRootViewController:viewController5];
/* Release View Controllers */
[viewController1 release];
[viewController2 release];
[viewController3 release];
[viewController4 release];
[viewController5 release];
/* Stuff Navigation Controllers into return value */
retval = [NSArray arrayWithObjects:viewController1,viewController2,viewController3,viewController4,viewController5,nil];
/* Release Navigation Controllers */
[navigationController1 release];
[navigationController2 release];
[navigationController3 release];
[navigationController4 release];
[navigationController5 release];
return (retval);
}
You Can Try This ....
Yes Howard, your approach is fine. Apple says this too. I also follow same approach while working with UITabbarController with UINavigationController and it works great for me.
You should have one UINavigationController per tab of your TabBarController. So your 2nd approach is correct. I don't think that you can reuse the same navigation controller for all the tabs.
Yes your approach is correct.
If u have to navigate views into tab then that tab should have navigation Controller.
UINavigationController * navigationCtrl = [[UINavigationController alloc] initWithRootViewController:firstTabViewCtrl];
[arrTabs addObject:navigationCtrl];
Either wise there is no need of navigation Controller inside tab.
[arrTabs addObject:firstTabViewCtrl];
I am making an application which will have 3 pages
Login Page - first page after the app loads
My First Page- when user successfully logs in then he comes into this page.This page
contains a UITabBar with two UITabBarItems. The first one is connected to
My firstPage
and the other one to My Second Page.
My Second Page - this is another UIViewController.
I have made the login page but I am unable to find the solution to UITabBar adding in My First Page
Please help me out
Define
AppDelegate.h
#property (strong, nonatomic) UITabBarController *tabBarController;
in AppDelegate.m
didFinishLaunchingWithOptions
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.delegate=self;
self.tabBarController.selectedIndex=0;
self.tabBarController.delegate=self;
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController{
return YES;
}
now when you get success login write below code in that method
AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
UIViewController *viewController1 = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
UIViewController *viewController2 = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
delegate.tabBarController = [[UITabBarController alloc] init];
delegate.tabBarController.selectedIndex = 0;
delegate.tabBarController.viewControllers = [NSArray arrayWithObjects:viewController1, viewController2, nil];
delegate.tabBarController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self.navigationController pushViewController:delegate.tabBarController animated:YES];
Try this out,
suppose this is LoginViewController.m
-(IBAction)loginButtonClicked:(id)sender
{
[self createTabBarView];
}
//Create TabBar View here
-(void)createTabBarView
{
NSMutableArray *tabItems = [NSMutableArray array];
UIViewController *firstViewController = [[FirstViewController alloc] init];;
firstViewController = #"First View";
firstViewController = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemContacts tag:0];
[tabItems addObject:firstViewController];
UIViewController *secondViewController = [[SecondViewController alloc] init];;
secondViewController = #"Second View";
secondViewController = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemContacts tag:1];
[tabItems addObject:secondViewController];
self.tabBarController = [[UITabBarController alloc]init];
self.tabBarController.viewControllers = tabItems;
self.tabBarController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:tabBarController animated:YES];
}
Thanks,
Nikhil.
Are you using interface builder?
From my point of view, I'd rather like to use programmatic way to implement it.
//In the appDidFinishLaunch method
BOOL loggedIn = [[NSUserDefault standDefault]boolForKey:"userlogin"];
if(loggedIn)
{
//Setup your UITabbarViewController
}
else
{
//Setup your loginView Controller
}
After login in LogInViewController
- (void)didLogin
{
YourAppDelegate *delegate = [UIApplication shareApplication].delegate;
[delegate.window addSubView:self.tabBarViewController.view];
[delegate.window removeSubView:self.view]
//Other Config
}
You should create Tabbar at place where you can identify that login is successfully done. This method should be part of your loginViewController.
Create a function like below to create a Tabbar and present it over loginController.
-(void) createTabBarController
{
UITabBarController *tabBar = [[UITabBarController alloc]init];
UIViewController *firstViewController = [[[UIViewController alloc] init]autorelease];
UINavigationController *firstNavController = [[UINavigationController alloc]initWithRootViewController:firstViewController];
firstNavController.tabBarItem.title=#"First Controller";
firstNavController.tabBarItem.image = [UIImage imageNamed:#"first.png"];
UIViewController *secondViewController = [[[UIViewController alloc] init]autorelease];
UINavigationController *secondNavController = [[UINavigationController alloc]initWithRootViewController:secondViewController];
secondNavController.tabBarItem.title=#"First Controller";
secondNavController.tabBarItem.image = [UIImage imageNamed:#"first.png"];
[tabBar setViewControllers:[NSArray arrayWithObject:firstNavController,secondNavController,nil]];
[firstNavController release];
[secondNavController release];
[self presentModalViewController: tabBar];
[tabBar release];
}