So I have a navigation controller that is at the beginning of a series of view controllers. The series consists of 5 view controllers, but I want the navigation controller to only use the first 4 view controllers. Im not sure if there is a way to change the relationship between view controller 4 and view controller 5 so that view controller 5 and the rest of the app are not affected by the navigation controller.
Im not sure if there is a way to change the relationship between view controller 4 and view controller 5 so that view controller 5 and the rest of the app are not affected by the navigation controller.
There are a number of things that you could do:
Remove the navigation controller entirely and make your "view controller 5" the window's root view controller.
Set the navigation controller's array of view controllers to an array that contains only "view controller 5." This would effectively make that view controller the navigation controller's root controller, and from there you could just never push another controller onto the navigation stack.
Keep the current relationship, but hide the navigation bar and prevent the user from going back to "view controller 4."
Rethink your user interface. For example, if your first four view controllers are meant to lead the user through some set of initial questions, a login procedure, etc., then you could make "view controller 5" the app's main view controller, and present the navigation controller containing the controllers 1-4 modally.
Of those, and without knowing what you're actually up to, I believe reconsidering your UI is probably the best plan. Users should generally be in control of your app instead of the other way around, and they should never wonder why they can't get back to some part of the app that they've seen before. Also, it's poor form to break behaviors that users have learned to expect, and changing the user's ability to navigate through a series of view controllers would be a prime example. Using a modal presentation of the navigation controller with the first four view controllers should be fine, though.
Related
I am creating an app using UItabBarController. I have 5 tabBar items at the bottom.
should I wrap navigationController in each item? Is that the best practice, and if not what's the best practice?
The tabs in a UITabBarController represent independent sections within an app. An example is Apple's Clock app. It has 4 tabs which are completely independent of each other.
A navigation controller represents a top-down hierarchy / stack of view controllers (meaning you start with a root view controller and then 'push' view controllers onto the stack. This almost inevitably means that it shows a 'logical flow'. You perform an action like selecting something on a view controller, which takes you into a more detailed view related to the action you performed. An example is Apple's Notes app which shows a list of folders of notes, selecting a folder pushes the screen with the list of notes in that folder onto the navigation stack, selecting a note in that list pushes the note that the user tapped on, onto the top of the list of notes.
Generally you should have tab bar controller as your app's root view controller and then each of the tabs could have a navigation controller as its root. It wouldn't usually have a tab-bar inside a navigation controller.
One case where a tab-bar could live inside a navigation controller is when a tabbed interface is presented modally.
To your question "should I wrap navigationController in each item", I think yes each tab should have a navigation controller as the root if a navigation hierarchy is required in that tab.
Hope this helps you.
So UIKit Framework Reference describes UINavigationController as an efficient way to present data and views to user. But I'm curious as to the performance and manageability differences between using UINavigationController VS SegueOnly.
There must be certain situations that one is better-suited than the other. I am entirely new to coding but instinctually I imagine UINavigationController is more for presenting VC's that each have a lot going on and user spends much time on each VC equally or that multiple VC's need to be running and holding data at same time. And that Segue are more for Uni-directionally VC progression or short-use, low-data VC presentations. Are any of these assumptions correct?
What are the PROS to implementing a UINavigationController?
This is an Apples to Socket-wrenches comparison. A navigation controller versus a segue isn't even an option. They don't fill the same role. You can use a navigation controller with or without using segues. You can use segues with or without a navigation controller.
A UINavigationController is a specific type of view controller. Specifically, it is designed for controlling a navigation stack of view controllers. When a user moves forward through your app, you add other view controllers to this navigation stack (either through segues or through other methods available on the view controller to present other view controllers). Meanwhile, the navigation controller allows you to "pop" controllers off the stack and we go backward to the previous view controller.
When we're comparing a UINavigationController to things, we should compare it to things like UITabBarController, or UISplitViewController, or UIPageViewController. These are other types of view controllers that control the way in which a user navigates through our app.
Segues exist as a means to get from one view controller to another. But the various controllers I just listed exist as a means for controlling the navigational relationship between your controllers.
If you are using storyboards for building your app, I highly recommend that you use segues. Whether or not you use a navigation controller is entirely up to the way you want your application navigation to work.
Perhaps some pictures might make the distinction more clear?
Exhibit A
Here we have two view controllers. No navigation controller, nothing. Just two normal controllers. The line with the arrow between the view controllers is the segue. The segue defines a relationship between the view controllers which lets us get from the one on the left to the one on the right.
Exhibit B
Here we have a navigation controller, followed by two view controllers. The line between the navigation controller (far left) and the first view controller (middle) is not a segue. However, it does define a relationship between the navigation controller and the view controller. It defines the view controller as the navigation controller's root view controller. Whenever we present this navigation controller, it will in turn present this view controller as the first controller on its navigation stack. The line between the first view controller (middle) and the second view controller (far right), however, is a segue. It's identical to the segue from exhibit A (except exhibit A is probably a different type of segue). This segue defines a relationship between the first and second view controller and provides us with a means of getting from first to second.
Exhibit C
Here we have a tab bar controller (far left) and four view controllers. We also have a bunch more lines connecting these things. Much line in the navigation controller example, the lines between the tab bar controller and the view controllers are NOT segues, but they do define a relationship between the tab bar controller and the view controllers. These lines assign the view controllers as part of the tab bar controller's viewControllers array, which determines what tabs to display. The lines between the left view controllers and the right view controllers, however, are segues, exactly the same as the first two examples.
A segue is nothing more than a way of defining a navigational relationship between two view controllers on your storyboard. If you weren't using a storyboard, you also wouldn't be using segues at all, but you could still make your app navigate in the exact same manner (this can all be achieved programmatically without the storyboard and without segues--and I don't think it effects performances on way or another).
Whether or not to use a navigation controller is another question and an entirely separate question at that. Whether or not to use a navigation controller isn't even remotely in the same ballpark to whether or not you're using segues. Using a navigation controller also isn't a question of performance. The overhead for using a navigation controller is extraordinarily minor. Most of the overhead for it probably comes from the UI stuff it adds... but if you want that UI stuff, you're going to have that overhead whether or not you have a navigation controller.
Importantly, whether or not to use segues isn't a question of performance--it's merely a question of whether or not you're designing your app using storyboards. And equally importantly, using navigation controllers isn't a question of performance--it's a question of how you want your app's navigation to look and feel. "Is a navigation controller the right look and feel for your app?" is literally the only question you have to answer when deciding whether or not to use a navigation controller.
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 am building an application that have an introduction at first when users do not login.
If they log in, when navigation controller will push to Home View Controller, but the Introduction View Controller is still in the stack and use a lot of resources. How can I prevent that?
You can set the navigation controllers property to array holding ur homeview controller alone. Or set the home view controller as root of navigation controller.
You can't prevent it from being there necessarily as that is a function of how you associate your views.
If you are happy with your current transitions (UI) then you should add a bit of code after the transition has completed which gets the nav controller view controllers array, removes the first object (the login / intro VC) and saves the new array.
If you want to change the transitions then you could look at presenting the login / intro as a modal so that when it is dismissed it is automatically destroyed.
I am creating a iPad App and it has several views to load data,but for one view i need to add split view. I dont need split views in other views. They are just detail pages. I search Through the net and found lots of tutorials based on iPad split view. But the problem is they all are creating a project as Split view project or they create a window base app and add slipt view to the delegate. I dont need to do that, I need to implement this split view only for one view. Is There any way to overcome this problem?
You can add the split view inside a Navigation Controller.
Even if the Split View is a container view controller and Apple recommends in the documentation that all containers should not be embedded in other containers, adding a split view inside a navigation controller works correctly and I never noticed any side effect in doing it.
Basically what you should do is:
- in the app delegate create a UINavigationController and use it as root view of your application window
- hide the navigation controller navigation bar if you don't want to see it (showing a split view with a main navbar on top is not nice looking...)
- then add your view controllers inside the navigation bar.
Example: imagine you have this application views sequence:
FIRST VIEW (full view = detail page)
SECOND VIEW (split view)
THIRD VIEW (full = detail page)
So you can represent FIRST and THIRD as standard view controllers (full screen), while SECOND will be a split view. Your app will be initialized by creating the main navigation controller, adding FIRST on it as top controller and using the main navigation controller as window's root view.
Than use the navigation controller push, pop methods to switch between these views or change the navigation controller "viewControllers" array directly if you don't want the recommended push/pop methods.
If you need to add special behavior to the navigation controller based on the type of view on top, just register your app delegate as navigation controller delegate (or a "main controller" object dedicated to this if you don't want to complicate your app delegate).
I am not 100% sure, but it seems to me that you can't use a SplitView just somewhere in your view hierarchy.
The Apple intended way is to use the SplitViewController as the top level controller. The left side of it can include a drill down mechanism with a navigation controller so you are ably to drill down hierarchies and the right side will present details for the item you select on the left side.
If you need a view with some kind of split mechanism in it, you probably have to code it yourself. Or even better: find some other mechanism you can use in your UI.
How are you switching your view hierarchies now? Maybe you could integrate your existing UI into a SplitViewController?