I'm using Storyboards for the first time. It's mostly going okay, but one situation is very unclear:
I'm using a Tab Bar Controller as my Initial View Controller. I have three tabs, and they're each an instance of the same view controller class, the only difference being that I want to pass in a different array to each instance, to display different data.
My thought was I could use prepareForSegue: in the UITabBarController instance to pass the proper array to each destination view controller…but maybe UITabBarController isn't using segues to display each view controller in a tab, because there's no way in IB to specify a Storyboard ID for the "segue" to the tab contents. (If I select the segue that connects the Tab Controller to the child Controller, IB just says "Not Applicable" in the customizer area.)
So my question is: how can I handle this situation in IB?
UITabBarController uses segues, but it is a special kind of segues. Select a UITabBarController in the IB, and open the Connections inspector in the Utilities area. You'll see that there are Presenting Segues in the bottom (those are handled by prepareForSegue) and Triggered Segues, which include viewControllers segues. Those are the segues to tabs inside a tab bar. They are not really segues, they are more like references.
In order to use one class for three different view controllers as tabs in IB, you should add three empty (or not) view controllers as tabs and specify their class using the Identity Inspector in the Utilities area. The class can be the same for all three.
Related
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.
I have an app which has 5 major user flows..each flow is a few screens linking to each other...so each flow warranties its own storyboard. Each storyboard starts with a custom view controller that is embedded in a navigation controller. So far so good.
Now all of this is "stitched" together via a UITabBarController. This is the most default UI design ever known to iOS.
But turns out I don't really know how to link from tabbarcontroller, which is in its own storyboard (that is set as the main one on code project) to any of the other storyboards.
This problem looks so! simple, so I think I am missing something utterly obvious, but I just can't figure out how to do it.
So how do I link from tab bar controller in storyboard 1 to the initial view controller in storyboard 2 when a tab is tapped?
You should do this in code. You can have the tab bar controller (tbc for short) and the controller in the first tab in the app's main storyboard, and in the app delegate, instantiate the other controllers using instantiateInitialViewController. Create a mutable array by copying the tbc's viewController array, add the other controllers you instantiated to it, and then set that array as the tbc's viewControllers array.
You have to add your viewcontroller programmatically in tabbar.
Difference between navigation controller and viewcontroller?
I mean how can we decide when to use navigation controller or a normal view controller?
Just my two cents:
A UIViewController represents a single view and you can put buttons in this view controller to segue to another UIViewController. If you want to segue back to the first UIViewController, you will have to worry about putting a button in the second view controller that leads back to the first. If you are drilling down into view controllers, this can be tedious having to remember to give the user a way back to a previous view controller.
A UINavigationController does a lot of this tedious work for you. As mentioned, it contains a stack of UIViewControllers. It will create a navigation bar at the top that will allow you to easily go back up the hierarchy of view controllers.
In short, if you have a hierarchy of view controllers that you want the user to easily navigate around, inbed your UIViewControllers into a UINavigation controller.
UINavigation Controller is a combination of 2 or more view controllers,those are connected through "segue" feature of "Ios". Benefit of using Navigation Controller is that we can navigate between different screens easily with default "Back" button on each screen . We don't need to give any individual button to move back onto previous screen.
Whereas a ViewController provides a single screen & we can connect more screen using "segue" but we also have to design a "Back" button to navigate onto previous screen.
We should use Navigation Controller , in case where one option resides into another one.Like in an iPhone settings ->Mobile Data Options->Voice->4G or 3G or 2G. It's a hierarchy of menus so here navigation Controller is better option than using UIController.
We should use UiController with "segue " , in case where
we have to choose one option among multiple.Like -
Photos ->There are many folders in which , any one is selected, that are Favourites or People or Places .
Here's a very brief, high-level overview.
Whereas a UIViewController can be thought of as representing a single 'screen', UINavigationController, as the name implies, is used as a means of being able to navigate multiple 'screens'.
From the 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.
Please see the rest of the UINavigationController documentation here: https://developer.apple.com/library/ios/documentation/UIKit/Reference/UINavigationController_Class/index.html
Okay, Thank you everyone for helping me to find out a clear answer on this.
Navigation Controller consists of navigation bar and tool bar to move in and out from view controllers present in navigation stack.Therefore there can be many view controllers in Navigation Controller.
In view controller we don't have this facility and it represents a single screen view.
Please correct me If I am wrong.
See the Navigation Controller discussion in the View Controller Catalog.
Bottom line, a navigation controller actually is a view controller, but it just happens to be one that presents and navigates between other view controllers.
I have a UIViewController in my Storyboard that can have one of two layouts, depending on which setting the user chose.
One uses a UITableView to display the information, while the other uses UICollectionView.
In code, I'd simply set up the view controller depending on the setting, but I don't see how I would do this with a Storyboard. How do I handle the multiple layouts in a Storyboard environment? (Worth mentioning this view controller is embedded in a navigation controller.)
This situation is no different than any time you have to make a choice in an app as to which controller should be shown next. Have two different navigation controllers (with storyboard identifiers) set up in the storyboard, one whose root view controller has the table view, and the other with the collection view. After the user makes a choice, instantiate the correct navigation controller, and segue to it, or make it the window's root view controller.
I understand that view controllers help control multiple views in an application, but I have trouble understanding when to use them.
If I have an application with a main page, several views with a "hierarchy" structure, and an about page not connected with the hierarchy, what files should my application have? An appdelegate, navigation controller and view controller? More than one view controller? Just a navigation controller?
Also, should they all be contained in one .xib file, or multiple .xib files?
Any help would be greatly appreciated.
Thanks.
A good habit is to have a UIViewController for each page you want to show. If I get the structure of your app you should have a main page (with many other UIViews inside it) and another page (about page). If that's true I suggest two UIViewControllers.
The UINavigationController is a subclass of UIViewController that lets you "navigate" among the pages. It's not strictly necessary but suggested (you can also implement your self a custom navigation system, but it's easier to exploit the one Apple offers you). Another navigation system is the one based on UITabBarController, if you want to take a look.
Assuming I get the structure of your app you should need two .xib file, one for each page you have.
The app delegate is conceptually different from a view controller, you'll have just a single app delegate, automatically created by Xcode (you can, of course, modify it to fit your needs).
Each "screenful of content" (Apple uses this term) should be handled by it's UIViewController or more likely a subclass of it. The point of view controller is to handle view appearing or disappearing (going on/offscreen), device rotation, memory management, navigating to other view controllers and so on. If you are creating your UI with IB, then each of those view controllers would most likely have it's own .xib file.
Each view controller has one view (it's view property) that acts as main view for each "screenful of content" to which you then add your subviews.
UINavigationController and UITabBarcontroller are there to help you control the hierarchy of your app. They only act as containers for other view controllers and don't contain any UI except navigation bar or tab bar. Using tab bar controller you can have multiple view controllers which act exactly like browser tabs. Using navigation controller you can have a stack-like navigation where new view controllers are pushed from right to left and are popped from left to right when user goes back to previous view controller. You can even have a view controller inside navigation controller inside a tab bar controller.
If you don't want to use tab bar or navigation controller, you can navigate through your view controllers by presenting them modally using presentModalViewController:animated: and dismissing by dismissModalViewControllerAnimated:. If you send YES for animated parameter of these methods, you will get an animation specified by the modalTransitionStyle property of view controller being presented or dismissed. Possible animations are slide in from bottom (default), horizontal flip of entire screen, fade in/out and half-page curl.
There are also some Apple-provided subclasses of UIViewController that help you setup your UI quicker like UITableViewController which is basically a view controller that contains a table as it's main view and conforms to 'UITableViewdataSourceanddelegate` protocols which are required to define how each cell looks and what it contains.
On iPad there is one additional container controller UISplitViewController and one additional way to present new view controllers using UIPopover.