I want to provide an opportunity to switch between 3 view controllers.I don't use navigation controller.Instead,I prefer tab bar.Here in xcode we have tab bar controller and tab bar.What are the purposes for providing independent tab bar object?I mean when you drag tab bar Controller it creates controller and 2 items and they already have tab bar.Doesn't it mean I can use it without view controller or what?
Yes, the UITabBar is an independent pre-defined UI element you can use wherever you want. Using it in combination with a UITabBarController gives you the benefits of handling events related to the UITabBar easily, since you don't need to implement most of the logic yourself.
UITabBar is inherit from UIView and while UITabBarController is inherit from UIViewController and responses to the protocols UITabBarDelegate and NSCoding.
Moreover UITabBarController provide automatic mechanism and logic - the other is more flexible in case you have to implement the things differently.
Related
I have a stack like below hierarchy (I'm using programatic way, so I done it)
UINavigationController -> UITabbarController -> UInavigationController -> UIViewController
-> UInavigationController -> UIViewController
As Apple Docs say for pushViewController:
The view controller to push onto the stack. This object cannot be a tab bar controller
I need to know If this has a known bug or will CERTAINLY causes a bug.
I really searched a lot for similar posts but none of them give me an acceptable answer.
Using UITabBarController with UINavigationController - Swift 3
Can you push a UITabBarController inside an UINavigationController
From Apple:
Before creating a tab bar interface, you need to decide how you intend
to use a tab bar interface. Because it imposes an overarching
organization on your data,you should use one only in these specific
ways:
Install it directly as a window’s root view controller.
Install it as
one of the two view controllers in a split view interface. (iPad only)
Present it modally from another view controller.
Display it from a
popover. (iPad only)
Installing a tab bar interface in your app’s main
window is by far the most common way to use it.
In such a scenario,
the tab bar interface provides the fundamental organizing principle
for your app’s data, with each tab leading the user to a distinct part
of the app. You can use tab bar controllers by themselves or in
conjunction with other view controllers to create even more
sophisticated interfaces. For more information, see Combined View
Controller Interfaces.
It is also possible to present a tab bar controller modally if a very
specific need makes doing so worthwhile. For example, you could
present a tab bar controller modally in order to edit some complex
data set that had several distinct sets of options. Because a modal
view fills all or most of the screen (depending on the device), the
presence of the tab bar would simply reflect the choices available for
viewing or editing the modally presented data. Avoid using a tab bar
in this way if a simpler design approach is available.
how to use material components tab bar to change the view controller
and embed all viewcontrollers in one single tab view item
(i want nested tab view one at top and one at bottom)
what i need is at this image
Have you tried using MDCTabBarViewController?
With it you can provide view controllers by instantiating them and providing them to its viewControllers property. You can also set the selectedViewController to provide the view controller that is initially presented. The MDCTabBarViewController has a tabBar property where you can customize the MDCTabBar to your needs.
Have a look at this example if you need more implementation guidance: https://github.com/material-components/material-components-ios/blob/develop/components/Tabs/examples/TabBarViewControllerExample.m
I have a TabBarController with 3 tabs set up in my storyboard. I want to have each tab have its own navigation controller. However, I don't want to embed each one in a nav controller, cluttering the storyboard and then having to style the navigation each time. Is there any way to do this programatically? In other words each time a tab is tapped, the resulting view controller will be set as the root of one existing navigation controller?
I don't think that there is a way to 'set' the rootViewController every time, but you can do 3 navigationControllers in your storyBoard and build a subclass of UINavigationController. That way you don't have to set it every time. Subclassing UINavigationController has become possible since iOS 6 (See documentation):
The UINavigationController class implements a specialized view controller that manages the navigation of hierarchical content. This navigation interface makes it possible to present your data efficiently and makes it easier for the user to navigate that content. You generally use this class as-is but in iOS 6 and later you may subclass to customize the class behavior.
In my app, I have to show same NavigationBar for all UIViewControllers. This NavigationBar has three buttons and these three buttons which will be act as TabBar functionality, that is each tab has its own stack cycle. I have created custom view for NavigationBar with three buttons, but after adding this custom view to HomeViewController, I have to manually add this custom view for all other view controllers. I don't want to do this.
Is there any simple method to achieve this?
There are a couple of ideas that come to mind. First of all, you could use view controller containment and actually have 1 controller that implements your custom nav bar, and then swap out the contained controller as necessary.
If that's not feasible, you can simply use inheritance and have all your custom controllers inherit from a controller that has the nav bar in place.
Another option could be to write your own UINavigationController subclass. I'm not certain if you can override the UNavigationItem behavior, but if you can, you can just just do that -- instead of the UINavigationController taking its child's UINavigationItem to update its own UINavigationBar, the UINavigationBar perhaps just stays the same, like you're expecting/hoping.
This may be a completely meaningless question, but I got lost. Why should one use tabbarcontroller instead of using tab bar and tab bar items?
As can be seen in the image, I can put a Tab Bar and Tab Bar Items inside a root view, so why should I use tabbarcontroller?
You use a UITabBarController when you want a simple way to switch between different view controllers using a tab bar.
You use a UITabBar when you want your own custom behavior attached to the tab bar.
A view (UITabbar) object knows how to display data to a user and accept user input. UITabBar is a subclass of UIView, display a list of tabs items to the user, and how to display feedback to the user when the user interacts with the tabs. UITabItems are similar to any other UIElements but specially designed to be used within UITabbar due to the unique design and property such as badges.
A controller (UITabbarController) object that knows what data to display to a user and what to do with user input. A UITabBarController is a subclass of UIViewController, It knows what tabs to display to the user, and what to do when the user chooses a tab. This class acts as a convenient base class from which you can derive your controller and also has property's that make it easier to reference when developing.