Error: Creating Tab-Navigation programmatically - iphone

Question

Excuse if this problem is posted already..
I want to create combination of TabBar and NavigationBar programmatically using XCode 4.2 & iPhone SDK 5.0
It produces visual as expected..but when a TabBarItem is pressed(taped) to change to its corresponding view, it is producing error: [__NSCFString _tabBarItemClicked:]: unrecognized selector sent to instance
Here is the implementation of the AppDelegat
#import "ApplicationDelegat.h"
#import "BrightnessController.h"
#implementation ApplicationDelegat
#synthesize window;
//#synthesize bControl;
- (void)applicationDidFinishLaunching:(UIApplication *)application
{
NSMutableArray *controllers = [NSMutableArray array];
UITabBarController *tbarController = [[UITabBarController alloc] init];
for (int i = 0; i <= 3; i++)
{
//self.bControl = [[BrightnessController alloc] initWithBrightness:i];
BrightnessController *bControl = [[BrightnessController alloc] initWithBrightness:i];
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController: /*self.bControl*/bControl];
nav.navigationBar.barStyle = UIBarStyleBlackTranslucent;
[controllers addObject: nav];
//bControl.tabBarItem = [[UITabBarItem alloc] initWithTitle:#"test" image:nil tag:i];
//tbarController.navigationController.delegate = self;
}
tbarController.viewControllers = controllers;
tbarController.customizableViewControllers = controllers;
tbarController.selectedIndex = 0;
tbarController.delegate = self;
// NSCFString
//tabBarItem
// Set up the window
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window addSubview:tbarController.view];
[self.window makeKeyAndVisible];
}
#end
I don't know why it happens and how to recover it..
Somebody help me.
If more detail is required, I can provide the source code...
Thanks in advance.

Answer 1

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController; 7:20
switch(mytabbar.selectedIndex)
{
case 0:
[imageView1 setImage:[UIImage imageNamed:#"Tab1_sel.png"]];
[imageView2 setImage:[UIImage imageNamed:#"Tab2.png"]];
[imageView3 setImage:[UIImage imageNamed:#"Tab3.png"]];
[imageView4 setImage:[UIImage imageNamed:#"Tab4.png"]];
[imageView5 setImage:[UIImage imageNamed:#"Tab5.png"]];
break;
case 1:
you can use this method and change on each tabbar click index

Answer 2

Two issues I see...
You assign the view of the tabBarController as a subView of the window. This is incorrect. You need to set the rootViewController of the window to be the tBarController.
Are you implementing the tab bar's delegate method tabBar:didSelectViewController:? Your error message says you're trying to send a tabBar-related method to an NSString. I suspect it's due in part to point (1). Try:
self.window.rootViewController = self.tBarController;

Answer 3

I typically prefer creating another tabbarview class that handles all the different view controllers, in which case, the app delegate will look like this:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
ViewController *viewController = [[ViewController alloc] init];
self.window.rootViewController = viewController.myTabBarController;
[self.window makeKeyAndVisible];
return;
}
And in ViewController I do this:
Header file:
#interface ViewController : UIViewController {
IBOutlet UITabBarController *myTabBarController;
}
#property (nonatomic, retain) IBOutlet UITabBarController *myTabBarController;
And in the implementation file:
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
exerciseViewController *viewController1 = [[exerciseViewController alloc] init];
viewController1.title = #"Exercise";
viewController1.tabBarItem = [[UITabBarItem alloc] initWithTitle:#"Exercise" image:[UIImage imageNamed:#"inbox.png"] tag:0];
UINavigationController *firstNavController = [[UINavigationController alloc]initWithRootViewController:viewController1];
bookViewController *viewController2 = [[bookViewController alloc] init];
viewController2.title = #"Book";
viewController2.tabBarItem = [[UITabBarItem alloc] initWithTitle:#"Book" image:[UIImage imageNamed:#"inbox.png"] tag:1];
UINavigationController *secondNavController = [[UINavigationController alloc]initWithRootViewController:viewController2];
askViewController *viewController3 = [[askViewController alloc] init];
viewController3.title = #"Ask";
viewController3.tabBarItem = [[UITabBarItem alloc] initWithTitle:#"Ask" image:[UIImage imageNamed:#"inbox.png"] tag:2];
UINavigationController *thirdNavController = [[UINavigationController alloc]initWithRootViewController:viewController3];
workshopViewController *viewController4 = [[workshopViewController alloc] init];
viewController4.title = #"Workshop";
viewController4.tabBarItem = [[UITabBarItem alloc] initWithTitle:#"Workshop" image:[UIImage imageNamed:#"inbox.png"] tag:3];
UINavigationController *fourthNavController = [[UINavigationController alloc]initWithRootViewController:viewController4];
myTabBarController = [[UITabBarController alloc] init];
myTabBarController.viewControllers = [NSArray arrayWithObjects:firstNavController, secondNavController, thirdNavController, fourthNavController, nil];
}
return self;
}
This is just an example...and I think it's the right way to do that.