R – UINavigationController doesn’t work in a the moreNavigationController of a UITabBarController

iphoneuinavigationcontrolleruitabbarcontroller

I'm dealing with UINavigationControllers in my application, all handled by an UITabBarController. Everything works fine until my controllers fall into the automatically generated "More" tab.

I reproduced the problem in the simplistic example. Am I doing something wrong? I can't figure out.

Thanks for your help.

#import <UIKit/UIKit.h>

@interface testAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate>
{
    UIWindow *window;
    UITabBarController *tabBarController;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
@end

@implementation testAppDelegate
@synthesize window, tabBarController;

- (void)applicationDidFinishLaunching:(UIApplication *)application
{
    tabBarController = [[UITabBarController alloc] initWithNibName:nil bundle:nil];

    UINavigationController *ctrl1 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl1.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFeatured tag:1] autorelease];

    UINavigationController *ctrl2 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl2.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFavorites tag:2] autorelease];

    UINavigationController *ctrl3 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl3.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemBookmarks tag:3] autorelease];

    UINavigationController *ctrl4 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl4.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemContacts tag:4] autorelease];

    // This one won't work
    UINavigationController *ctrl5 = [[[UINavigationController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl5.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemMostRecent tag:5] autorelease];

    // This one will work
    UIViewController *ctrl6 = [[[UIViewController alloc] initWithNibName:nil bundle: nil] autorelease];
    ctrl6.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemDownloads tag:6] autorelease];

    tabBarController.viewControllers = [NSArray arrayWithObjects:ctrl1, ctrl2, ctrl3, ctrl4, ctrl5, ctrl6, nil];

    [window addSubview:tabBarController.view];
    [window makeKeyAndVisible];
}

- (void)dealloc
{
    [tabBarController release];
    [window release];
    [super dealloc];
}

@end

Best Answer

Short answer: you cannot nest navigation controllers

Longer answer: you are doing it wrong. A better way to create what you want goes like this:

NSMutableArray *viewControllers = [NSMutableArray array];

[viewControllers addObject:[[[ConverterViewController alloc] init] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[CurrencyViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[HistoryViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[SetupViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[UINavigationController alloc]
                             initWithRootViewController:[[[HelpViewController alloc] init] autorelease]] autorelease]];
[viewControllers addObject:[[[LinksViewController alloc] init] autorelease]];

self.viewControllers = viewControllers;
self.customizableViewControllers = [viewControllers arrayByRemovingFirstObject];


@implementation HelpViewController

#pragma mark -
#pragma mark Initialization

- (id)init
{
    if ((self = [super initWithNibName:@"HelpView" bundle:nil]) != nil) {
        self.title = NSLocalizedString(@"Help", @"Help"); 
        self.tabBarItem.image = [UIImage imageNamed:@"question.png"];
    }

    return self;
}

Related Solutions

Objective-c – Correct way to alloc/init instance variables in Objective-C

Does he create a custom setter for the controller instance variable?

If so, there may be code which is called when the controller variable is changed through the setter. Merely setting the controller variable with:

controller = [[GLViewController alloc] init];

would not invoke the setter method; however, assigning the newly allocated object to a local variable then setting it with:

self.controller = theController;

would invoke the setter method since it is a shorthand way of writing:

[self setController:theController];

and the extra code in the setter would be executed. This is commonly where you would expect the differentiation between the two methods.

Edit:

Evidently, after taking a look at the code, he doesn't implement a custom setter method, however the method that he has used is still most commonly used when a custom setter method would be implemented.

My guess at the reason behind the extra code would be that he plans to release the variable after allocation, and if assigned to a local variable, he can call the setter method with the local variable and then call release on the local variable afterwards. This would be overall more readable than using

[[self controller] release]

However, it is an odd way to do it, as the synthesized implementation of the setter will retain the instance variable, yet he then releases it once it has been set to the instance variable, and as the release call cancels out the retain call, it would make more sense to set the variable using the one-line method.

Ios – didEnterRegion of LocationManager not called ever

is your header file declared as a CLLocationManagerDelegate?

once you setup the region for monitoring you should test by removing that element of the code and then check for the UIApplicationLaunchOptionsLocationKey key when launching like this:

 if ([launchOptions objectForKey:@"UIApplicationLaunchOptionsLocationKey"]){

        NSLog(@"UIApplicationLaunchOptionsLocationKey - fired");
        if(locman == nil){
            locman = [[CLLocationManager alloc]init];


        locman.delegate = self;
        locman.distanceFilter = kCLLocationAccuracyBest;
        }

    }

The location manager delegate will then be called and didEnter and didExit should fire ok.

Best Answer

Related Solutions

Objective-c – Correct way to alloc/init instance variables in Objective-C

Ios – didEnterRegion of LocationManager not called ever

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