When we want to create an application that contains different functionality related with the use of the application, but independent between them, like showing data in different ways or different tasks, we will want to use a Tab Bar in our application.

The Tab Bar will gave us acces to this different views, like independent modules, more over, it helps the user to place himself inside the application, telling him what he is seeing.

Today we will give basic indication to create and set up a Tab Bar in our application. In Xcode we have a template which will create an application with a Tab Bar and two different views, although it is a good start point, when we take a look to the code we can see much of what it’s going on, that because they use Interface Builder to do almost all the setting up. We will show a bit more of code.

Structure

We have an application, inside there is our Tab Bar, we need to tell the Tab Bar which views (UIViewController) it has to show, each view will take care of itself, but we need to setup the property tabBarItem (UITabBarItem) for each view so the Tab Bar can show us the icon and title of it.

Data

The only thing we need is an icon for each view and a title. We can use both at the same time or only one of them, of course, a Tab Bar only with a title doesn’t look right so I will recommend at least to use an icon to represent what is done in that tab. The title is always welcome when the icon is not clear what represents.

The title isn’t more than a normal string that we will give in the code, but the icon is a bit more tricky and although Apple give as some system icons to use, take a look at UITabBarSystemItem, they also tell us how we have to create our own icon.

▪ Use PNG format.
▪ Use only pure white with proper transparency.
▪ Don’t add shadows.
▪ Use anti-aliasing.
▪ Size of 30 x 30 pixels.

Code

To create the Tab Bar and add it to the application use this

- (void)applicationDidFinishLaunching:(UIApplication *)application {
 
tabBarController = [[UITabBarController alloc] init];
 
MyViewController* vc1 = [[MyViewController alloc] init];
 
MyOtherViewController* vc2 = [[MyOtherViewController alloc] init];
 
NSArray* controllers = [NSArray arrayWithObjects:vc1, vc2, nil];
 
tabBarController.viewControllers = controllers;
 
[window addSubview:tabBarController.view];
 
}

We create the Tab Bar, the view controllers we need and put those in an array to tell the Tab Bar those are the one it has to show. We add the Tab Bar view to the window and we are finished.

To set up each of the UITabBarItem of each view we can use the following lines

UIImage* anImage = [UIImage imageNamed:@"MyTabBarIcon.png"];
 
UITabBarItem* theItem = [[UITabBarItem alloc] initWithTitle:@"TabBarItemTitle" 
                                                     image:anImage tag:0];
 
[myViewController setTabBarItem:theItem];

Usually we will put these lines in the view controller itself, on the init method, but might be necesarly to do it in some other place when we are not using our own classes, for example when one of the tabs uses a Navigation Bar, in that case we can put these lines just after creating the Navigation Bar.

Si señores, después de mucho tiempo inadvertido por fin, gracias a nuestros usuarios, hemos conseguido el codiciado puesto número 1.
Llavemos ya 4 días en el primer puesto de aplicaciones de utilidad y 4 días días en el top 10 del ranking global de AppStore España.
Gracias a todos vosotros !

Un equipo de desarrollo español (Ivanovich Games), amigos de ZenBrains acaba de anunciar su última creación: iRemoteDog.

Es una idea genial y muy original. La aplicación consiste en un mando de distancia que permite dar ordenes sonoros a tu perro.

Claro, esta app no hace mágia, primero tienes que entrenar a tu perro para que aprenda esos sonidos.

Se usan un tipo de sonidos que son inaudibles para los humanos pero muy fácilmente reconocibles por los perros.

A parte  para los perros es más fácil entender y diferenciar este tipo de sonidos que la palabras.

Una vez entrenado, puede ser de los más gracioso hacer espectáculos para los amigos, nadie quedará indeferente:¿Controlar un perro con el iPhone, WOW?

Desde aquí deseamos suerte al desarrollador del programa y recomendamos la aplicación.