I created a UInavigation controller in my xib file. The UINavigation controller is the top level control. I don't need a parent view. Later on I will manually add the UINavigation controller to the window.
What is the best way to instantiate the UINavigationController? I can't seem to figure out how to do this.
If you do not need to do anything special in the .xib file it is way easier to do this programmatically by adding the following code to your app delegate:
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:myView]; //myView is a view you previously created
[self.window addSubview:nav.view];
Related
Initially I used the IB to drag a navcontroller onto my tabbar and then setting the root controller. However, I'm trying to create a nav controller without IB.
What I've done is created a navcontroller subclass that will be used in my tabbar. The nav bar does show up so I know that is working.
Now, I need to push a viewcontroller into the hierarchy. In the nav controller's viewDidLoad:
- (void)viewDidLoad {
InfoViewController *initialController = [[InfoViewController alloc] init];
[self.navigationController pushViewController:initialController animated:YES];
[initialController release];
[super viewDidLoad];
}
I get no errors, but nothing shows up in the navigation controller. Anyone know why?
What does your InfoViewController's init method look like? If you're using a nib to build that, then you need to call initWithNib, not init.
Create the viewcontroller when/where you create the navigation controller (and add them to it) then add the list of view controllers to the tabbar.
I am working on my first iPhone app and making good progress. But there is one thing I just don't understand.
When my app starts it displays a UIView with some functionality on it. This works fine. One of the buttons on that screen is supposed to load a new view (HistoryViewController) which contains a navigation controller.
The problem is… whenever HistoryViewController is loaded the app crashes because there is no view. It's true because in the xib-File I can't connect the File's Owner's view to anything:
http://www.freeimagehosting.net/image.php?1a3caa8b8d.png
I definitely have a lack of knowledge somewhere but after hours of research I have not been able to solve this problem.
Any hints?
Thank you!
Normally you would either:
click on that bottom line (History Table View Controller, "HTVC") and in the inspector window specify a NIB Name - which means you would first have to make a new NIB.
or
doubleclick that bottom line (HTVC), so the 320x480 preview window pops up, and then drag in a UIView from the library.
Using the first method, you tell the view controller to dynamically load the NIB as the view to connect, and using the second method you do this for the view controller using IB. The view you drag in will then show up as a child of that bottom line (HTVC).
edit to actually load the nib file you created, do this to push the view controller:
UIViewController *controller = [[UIViewController alloc] autorelease];
[controller initWithNibName:#"nibfilename" bundle:nil];
[self.navigationController pushViewController:controller animated:YES];
substituting UIViewController for your own view controller class (if needed) and nibfilename with the filename of the nib (minus the extension!)
It's hard to tell what your problem is exactly, but I'll offer some advice.
When creating a navigation controller (or tab controller for that matter) in interface builder, its easy to not understand what is really happening, so my suggestion drop interface builder for a second and lets build it in code.
In general I really dislike building either UI Navigation Controller or tab view controller in interface builder, I really just rather build the views themselves and create the UINavigationController in code.
You have a view which shows the HistoryTableViewController which you want to be contained in a UINavigationController so the code to do this is:
- (void) showHistory
{
HistoryViewController *historyVC = [[HistoryViewController alloc] init];
// If you create historyviewcontroller in nib
// HistoryViewController *histroyVC [[HistoryViewController alloc] initWithNibName:#"myNib" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc] initWithRootController:histroyViewController];
[self presentModalViewContoller:navController animated:YES];
}
This will create a nav controller showing your history view controller as the root view controller. Can't be easier.
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:windowObj];
Can i do this?
Making a window as RootViewController with Navigation Controller upon it.
-initWithRootViewController: takes an UIViewController as its argument. Passing an UIWindow instance instead won't work. You can however use the view of the navigation controller as your applications main view.
I just realised that my 'root' viewController should have been a UINavigationController. Now I want to change this to be a UINavigationController instead and just curious what my best option would be. I built this view and all other views using IB if that makes a different.
I'm mostly worried that I would have to do a lot of copy/pasting and recoding to get everything right or will be it be as easy as manually editing my controller and change the extension to UINavigationController.
Thanks
You do not convert an existing view controller into a navigation controller.
Even though UINavigationController is a subclass of UIViewController, it's task is the management of other view controllers, not the management of views themselves. You don't swap them out one for the other. Instead, you set UIViewControllers to be controlled by the nav.
To add a nav to a project in IB, open the xib and drag over a UINavigationController. Then set the navigation controller's rootControlller property to the existing UIViewController.
And you're done.
You can also "Embed" the Navigation Controller by selecting the View Controller in IB then select Editor->Embed In->Navigation Controller
You can instantiate a trivial not-subclassed UINavigationController and give it your original UIViewController as its root controller, like:
YourRootViewController *rootViewController = [[YourRootViewController] initHoweverYouInitIt];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:rootViewController];
and maybe an [rootViewController release];, depending on how you are going to manage memory.
UINavigationController has an 'is-a' relationship with UIViewController, so you should be able to change its class type in Interface Builder with no additional changes.
I think I've found the cause: Document Info window in IB has a warning: "'Selected Navigation Controller (Second)' has nib name property set to 'SecondView.nib', but this view controller is not intended to have its view set in this manner."
Bummer.
I've built nib in Interface Builder that has UITabBarController at top level and switches between UINavigationControllers.
It works fine when everything is in a single nib file, but I'd like to use separate nib files for UINavigationControllers.
Starting with Apple's TabBar template, if I just change class of SecondView to UINavigationController, it all breaks:
and all I get is this:
// imgur has lost the image, sorry //
Is it possible to have separate file for UINavigationController without programmatically setting everything?
I would like TabBarController to handle loading and unloading of nibs.
Simply swap the UINavigationController with the FirstViewController.
So the hierarchy should be like this:
Tab bar controller
-----Tab bar
-----Navigation Controller
----------First View Controller
---------------Navigation Item
----------Tab bar item (First)
-----Navigation Controller
----------Second View Controller
---------------Navigation Item
----------Tab bar item (Second)
You set the nib of First View Controller in the inspector to the nib file containing the actual view objects (Since you are trying to split them into separate files, which is a good thing).
You have one tab, that tab has a navigation controller which loads First View Controller as its root view.
Done.
I haven't tried setting up UINavigationController via IB. I have multiple screens, each is stored in separate xib and there's a corresponding class that extends UIViewController. In applicationDidFinishLaunching I initialize UIViewControllers using xib's but then manually create UINavigationController, add navigation controller's view to window and push first view to navigation controller.
Not sure if that helps.
- (void)applicationDidFinishLaunching:(UIApplication *)application {
navigationController = [[UINavigationController alloc] init];
FirstViewController * viewController = [[FirstViewController alloc]
initWithNibName:#"FirstView"
bundle:nil];
[navigationController pushViewController:viewController animated:NO];
[viewController release];
[window addSubview:navigationController.view];
[window makeKeyAndVisible];
}
Above FirstViewController extends UIViewController, in IB you create your view then set File's owner class to your class (e.g. here FirstViewController) and connect the File's owner view to the UIView's view.
I believe you are looking for something like this. You would replace "whatever" with the name of you second nib file.
newNavController = [[UINavigationController alloc] initWithNibName:#"whatever" bundle:[NSBundle mainBundle]];
First, it looks like you have your UITabBarItems under the navigation controllers instead of directly under the UITabBarController. That may be part of your problem.
Second, when you add a UITabBarController in IB and and click on its icon in your list of top-level objects (your first screenshot), the attributes inspector will allow you to change the type of view controller for each of the tabs. Using this, you can change them all to navigation controllers, if you wish. Also, since you wanted to load custom views and view controllers from other nibs, if you look at the "View Controller" section at the bottom of the attributes inspector, you can select a nib from your project to load the view from. Assuming that nib's "File's Owner" is set to your UINavigationController subclass, it should all work fine.
All of this without a large amount of coding work, either. Let me know if you'd like screenshots for what I'm talking about in case you can't find these panels.
I found the same warning.I have kept all view controller in separate xib files. I got rid off it by removing .nib name and keeping it empty.