In my app, i have a main view controller which sometimes brings a modal view on top of it. This modal view is a UINavigationController with a navigation bar. I want to display an image above the navigation bar, and have the navigation bar appear below the image.
I do not want to subclass anything and the app uses autolayout, i do not want a bunch of delegate callbacks and frame calculations. The view inside the navigation controller (the actual modal content) must still respond to different screen sizes correctly, such as rotation, call status bar etc. Also, no IB solutions please, these views are all managed in code.
How do i accomplish this?
I would turn off AutoLayout and place the image at the top
I don't think you can do it with your modal view being a navigation controller. I would do it by making that modal controller a UIViewController that you set up as a custom container controller. You can add an image view to the top of this controller's view and add the view of a child view controller (which would be a navigation controller) to the bottom. This would be a lot easier to do in a storyboard using container views, but it certainly can be done in code.
Related
I'm getting a weird bug since using PageMenu library. This library adds the ability to swipe between view controllers or change current view controller via UISegmentedControl (on the top).
When the view controller is a UINavigationController, all UIBarButtonItems in the navigation bar are sticking to the borders, like this :
The two items are sticking to the borders of the screen. The same thing happens with Back button after pushing to a view controller.
The bug disappear if I present a view controller modally in the app.
Does anybody has a solution for this ? Or at least a workaround to simulate "presenting a view controller modally" at app launch ?
I was going through Apple's documentation about navigation controller and find this point ambiguous and hard to comprehend.
It was written in this online documentation of navigation controller.
Navigation Controller Views
A navigation controller is a container view controller—that is, it
embeds the content of other view controllers inside of itself. You
access a navigation controller’s view from its view property. This
view incorporates the navigation bar, an optional toolbar, and the
content view corresponding to the topmost view controller. Figure 2
shows how these views are assembled to present the overall navigation
interface. (In this figure, the navigation interface is further
embedded inside a tab bar interface.) Although the content of the
navigation bar and toolbar views changes, the views themselves do not.
The only view that actually changes is the custom content view
provided by the topmost view controller on the navigation stack.
From that, my understanding is that inside this "view" property. There should be at least two subview inside this view.One is the navigationBar the other is the contentView of the current displayed viewController’s view. But while I am debugging only the navigation bar showed with another view called UINavigationTransitionView showed.
My question is, is this normal. Have I done anything wrong?
Second, what is the most common way to access current displayed viewController's view with only the reference to the navigation controller.
Thanks
UINavigationTransitionView controller contains one wrapper view which intern will have the current uiviewcontroller's view.
You can probably find this view as a subview of UINavigationTransitionView. However this is not the "right" way to do this. The proper way is to go through property "topViewController" and then take its view:
self.navigationController.topViewController.view
If there is another view controller or its view that you need, you have access to whole view controller's hierarchy across navigation controller through viewControllers property.
self.navigationController.viewControllers
More here:
https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UINavigationController_Class/index.html
I know it's possible to set a background image for the UINavigationBar, but I would like to know if there is a way to share a common background view for all controllers in a UINavigationController. The idea is to have a UIImageView as the background that stays in place rather than "sliding" over itself when navigating to a new controller.
A navigation controller is a kind of view controller and it hosts the currently visible view controller by adding the VC view to its view. You can add things to that view too. Create your image view and add it as a subview of the nav controller view, then send it to the back (or insert at index 0).
I've seen a lot of other questions on here about adding a UINavigationBar to a UIPopoverController. All of the examples I've seen follow one of two patterns:
In the init or viewDidLoad method of the Popover subclass, you alloc-init a UINavigationBar directly, as suggested here. This method is a little hacky, and while it shows up nicely, if the popover is a UITableViewController, you have to mess with a bunch of things to make sure the navigation bar you just added doesn't overlap one of your cells.
Alternatively, a lot of post suggest creating a UINavigationController just before presenting the popover, as shown here.
With the second method, however, won't the popover be the only controller in the newly created navigation controller? And if my view that I'm presenting the popover from is itself already in a navigation controller, the popover will NOT be in that same navigation controller, correct? It seems to be that the more appropriate thing to do would be to add the popover being created as another controller in the navigation controller that already exists (and which the controller that presents the popover is already a part of). Is that possible? Or is there a reason why the navigation controller for the popover needs to be independent from the navigation controller for the presenting controller? Or am I totally missing something here?
You have many questions, young Skywalker. :)
Creating a UINavigationController and then embedding the controller you would like to present is the way to go.
Don't get confused by all the controllers involved here:
UIPopoverController is a construct that shows an existing UIViewController in an overlay like style. UIPopoverController itself even isn't a subclass of UIViewController. The name is misleading.
So UIPopoverController hosts another controller. In your case, we let it host a UINavigationController.
UINavigationController is a subclass of UIViewController. It is a container controller and can handle a stack of UIViewControllers.
On that stack we push one UIViewController: the one you want to display and garnish with a UINavigationBar. Since Mr. UINavigationController comes with a build in UINavigationBar, he's our friend.
There is no need to subclass UIPopoverController. You just keep one static reference to it around so you can dismiss the current open popover in case you want to present another.
It does not matter where you present the UIPopoverController from. It will always be a popover. Even if presented from an existing UINavigationController. Only if you use presentViewController: you will get different results depending on the controller you're presenting from (modal or pushed on top of the stack).
won't the popover be the only controller in the newly created navigation controller?
No, the popover will contain the navigation controller and the navigation controller will only contain its root view controller (which would otherwise have been added directly to the popover as its root).
You seem to be a little confused about the relationship between the popover and the popover root view controller...
the popover will NOT be in that same navigation controller, correct
Yes, correct. The popover is effectively a window floating above all other views
Or am I totally missing something here?
Maybe... The popover would usually be used for displaying something modal, transient and smaller than full screen size. Putting a navigation controller in the popover and adding views to it is the normal approach.
Adding a navigation bar to a popover isn't hacky. A navigation bar is just another regular view. That also means that using a UITableViewController with it, the navigation bar will overlap the table view, as the UITableViewController's view property just returns the controller's tableView property. If you want to add a navigation bar above a table view, without it overlapping the table view, use a regular UIViewController and add your navigation bar and table view the normal way. UITableViewController should only be used if your only view within that view controller is a table view.
Having said that, I do agree with others that just using a navigation controller without using its navigation features is the most common approach.
Below is a storyboard of my app. For some reason, some of the screens have a navigation bar on top, and some do not. How can I add the navigation bar to each of the screens? Any thoughts on what I did incorrectly for this to happen?
Thanks!
There's a couple gotchas here to be aware of:
The Simulated Metrics, as mentioned by #ohr, are just there for convenience when laying out your views. This lets you account for potentially having the 44px navigation bar in place, so you know to layout your UI elements on your view accordingly. This does not mean you have a navigation controller (or navigation bar) actually within the view.
To have a functional navigation bar, you have a couple options:
1) In your Storyboard, embed your UIViewController within a UINavigationController. This can be done by clicking Editor in the Menu, then Embed in -> Navigation Controller. Make sure you have your desired view controller in the storyboard selected.
2) If you just need a one-off navigation bar (say you are displaying a modal and don't need to push views onto the view hierarchy), then you have the option of just dropping a UINavigationBar into your storyboard view controller. You'll just need to wire up the buttons to IBActions to have them perform the desired task.
Hope this helps!