presentModalViewController and navigationController - iphone

I want to know the differences between the
[self presentModalViewController:controller animated:YES];
and
[self.navigationController pushViewController:controller animated:YES];
I have used both but still do not know or noticed the difference. when should use one of them ?
Thanks..

Basic difference :
pushViewController only works in navigation controllers
presentModalViewController works for all view controllers
navigationController is the instance of your UINavigationController, which is used by all the controller in your navigation stack (UIViewController).

Presenting a modal view is presenting a view on top of another view. You perform those typically for "tasks" that need to be started and completed in a self contained way. Read further on modal views on the apple developer guides.
Pushing a view on to the navigation controller is different where there is a logical need for navigation in the app. Say a drill down table as in the setting app of the iDevices, where there are main settings then you drill down to sub settings etc.
Whatever your questions are, if they are conceptual and generic as this I'd strongly advise you to google up "X programming guide" which will take you to the proper Apple programming guide :) X = view controller in your case
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/Introduction/Introduction.html

if base class has it's own NavigationController then you can write:
[self.navigationController pushViewController:objMyViewController animated:YES];
if your base class has only UIViewController then use:
MyViewController * objMyViewController = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:nil];
UINavigationController * navController = [[UINavigationController alloc] initWithRootViewController:objMyViewController];
navController.navigationItem.leftBarButtonItem = nil; // make nil if you want
// to use it in next View
[self presentModalViewController:navController animated:YES];
now, MyViewController has navigation so you can -- Push -- another viewController by writing function as bellow in MyViewController.
-(IBAction)btnNext_click {
SecondViewController * objSecondViewController = [[SecondViewController alloc]initWithNibName:#"SecondViewController" bundle:nil];
[self.navigationController pushViewController:objSecondViewController animated:YES];
}

Related

Can I not 'pushModalViewController'?

I have a UIViewController class and a second which I want to push modally preferably. However I can't seem to call [self pushModalViewController:...], how come?
What requirements do I need to meet to be able to do so?
I am doing this and getting a black view pushed:
vc = [[ViewController alloc] init];
[vc setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentModalViewController:vc animated:YES];
I have made my view controller in my storyboard and given it a custom class. I am trying to present this view modally via this class as seen in my code.
Any help much appreciated, thanks.
'push' and 'modal' don't belong together in the same thought. You can:
present a modal view controller, preferably using -presentViewController:animated:completion:, which is the modern replacement for -presentModalViewController:animated:
push a view controller onto the navigation stack, assuming that you're using a UINavigationController. To do that from a view controller, use:
[self.navigationController pushViewController:foo animated:YES];
You're actually looking for [self presentModalViewController:myViewController.view animated:YES]
How are you initing this viewcontroller. From the posted code, I assume it is being initialized to a blank view.
Maybe you can init it from a nibname or something?
vc = [[ViewController alloc] initWithNibName:#"NibName" bundle:nil];
[vc setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentModalViewController:vc animated:YES];
Also another thing to note, if this is a custom class and no nib file, is there any code in initWithCoder? How does the viewDidLoad looks like?

don't understand how to use navigation controller in iphone

I'm extremly new to iphone and I have the following misunderstanding.
All over internet the tutorials about how to use NavigationController programatically it says:
NavigationController must be declared in applicationDidFinishLaunching and must be init with a root.After that you can add views to it.
I have this:
A UIViewController class meaning(AdiViewController.h, AdiViewController.m and AdiViewController.xib) and no Delegate file meaning no applicationDidFinishLaunching method.
What I wanna do is from my class-AdiViewController when pressing a button to go to another view.
I understand that I need a NavigationController which should retain my views having the root AdiViewController.
But my problem is where should I initializate that NavigationController in viewDidAppear??...cause I don't have the Delegate files.
If you could provide a minimal example with this small issue of mine it would be great.I'm sure that for those how are senior this is nothing but still I don't get it.Thanks
NavigationController must be declared in applicationDidFinishLaunching -> this is not true.
In your AdiViewController if you have button when you push that button you want to load navigation Controller right ?
// Hook this IBAction to your button in AdiViewController
- (IBAction)pushNavController
{
AnotherViewController* rootView = [[AnotherViewController alloc] initWithNibName:#"Anotherview" bundle:nil];
UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:rootView];
[rootView release];
[self presentModalViewController:navController animated:YES];
[navController release];
}
If you are in AnotherViewController i.e., you are in root view controller of Navigation controller. You need to push and pop view controllers from there. For example if you have a button in AnotherViewController:
// push next view controller onto navigation controller's stack
- (IBAction)pushNextViewController
{
NextViewController* nextView = [[NextViewController alloc] initWithNibName:#"NextView" bundle:nil];
[self.navigationController pushViewController:nextView animated:YES];
[nextView release];
}
// Similarly if you want to go back to AnotherViewController from NextViewController you just pop that from navigation controller's stack
- (IBAction)pushNextViewController
{
[self.navigationController popViewControllerAnimated:YES];
}

Accessing a Top Navigation Controller from a Subview Navigation Controller

I have a my views and controllers set up like so.
A Tab/Bar controller
Within 1. is a root view controller
within 2. is a programmatically created navigation controller, that is displayed as a subview in the root view controller.
What I am trying to do is access the top tab bar/navigation controller so that i can push a view onto it.
I tried parentViewController but all it did was push the view onto the programmed nav controller.
any suggestions?
This is how i set up my root view controller:
-(void)viewDidAppear:(BOOL)animated{
NSLog(#"ROOT APPEARED");
[super viewDidAppear:animated];
WorklistViewController *worklistController = [[WorklistViewController alloc]initWithNibName:#"WorklistView" bundle:[NSBundle mainBundle]];
UINavigationController *worklistNavController = [[UINavigationController alloc] initWithRootViewController:worklistController];
worklistNavController.navigationBar.barStyle = UIBarStyleBlackOpaque;
worklistNavController.view.frame = watchlistView.frame;
[worklistNavController.topViewController viewDidLoad];
[worklistNavController.topViewController viewWillAppear:YES];
[self.view addSubview:worklistNavController.view];
GetAlertRequestViewController *alertsController = [[GetAlertRequestViewController alloc]initWithNibName:#"AlertsView" bundle:[NSBundle mainBundle]];
UINavigationController *alertsNavController = [[UINavigationController alloc] initWithRootViewController:alertsController];
alertsNavController.navigationBar.barStyle = UIBarStyleBlackOpaque;
alertsNavController.view.frame = alertsView.frame;
[alertsNavController.topViewController viewDidLoad];
[alertsNavController.topViewController viewWillAppear:YES];
[self.view addSubview:alertsNavController.view];
}
A nested ViewController (ie, inside a view controlled by a ViewController that's actually on the NavController stack) doesn't have direct access to the UINavigationController that its parent's view's controller is a stack member of. That's one MOUTHFUL of a sentence, but the sense of it is: you can't get there from here.
Instead you've got to get at the app's NavController via the App delegate.
YourAppDelegate *del = (YourAppDelegate *)[UIApplication sharedApplication].delegate;
[del.navigationController pushViewController:nextViewController animated:YES];
You're using your UIApplication's singleton (contains all sorts of good info about your app), which has a .delegate property pointing to the AppDelegate, and that contains a reference to the NavigationController.
This is how the "Navigation-based Application" Xcode template sets up NavController ownership, anyway. YMMV if you rolled your own--though if you did, you probably wouldn't need to ask this question.
You can use the follow instruccion:
[(UINavigationController *)self.view.window.rootViewController pushViewController:vc animated:YES];
It works for me :D
Have a look at UIViewController's navigationController and tabBarController properties. These will return the corresponding navigationController or tabBarController that the given UIViewController 'belongs' to.
So you can do something like:
[customController.navigationController pushViewController:newController animated:YES];
// Similarly for tabBarController ...

presentmodalviewcontroller navigationcontroller

I am creating a Navigation based iPhone application.
In that I have called a UiViewController using presentModalViewController. After that, the ViewController becomes visible. From that ViewController I need to call another ViewController using the sample presentModalViewController. Is this possible or not?
What do you mean by "call another uiviewcontroller"? (It really helps if you can be more detailed in your question.) If you mean, "slide in another view controller", then:
MyNewViewController *myNewViewController = [[MyNewViewController alloc] initWithNibName:#"MyNewViewController" bundle:nil];
[navigationController pushViewController:myNewViewController animated:YES];
[myNewViewController release];
...where:
MyNewViewController is the new view controller class that you want to slide in (the above code assumes you have an XIB file for the view controller class).
navigationController points to the current navigation controller. You'll have to replace it with something like [self navigationController], depending where you are in the view hierarchy.
U might be using following line to present a view controller.
//assume name of viewController which u want to present is "myViewController"
[self.navigationController presentModalViewController:myViewController animated:YES]
If you want to push an other ViewController or present an other ViewController then u will need to replace above line with following lines.
//[self.navigationController presentModalViewController:myViewController animated:YES];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:myViewController];
navigationController.navigationBarHidden = YES; //if u want to show navigation bar then remove this line
[self presentModalViewController:navigationController animated:YES];
After using above code you can present or push other view controllers within presented view controller.
Hope it will solve your problem :)

iPhone modal view inside another modal view?

My App uses a modal view when users add a new foo. The user selects a foo type using this modal view. Depending on what type is selected, the user needs to be asked for more information.
I'd like to use another modal view to ask for this extra information. I've tried to create the new modal view like the first one (which works great) and it leads to stack overflow/“Loading Stack Frames” error in Xcode.
Am I going about this in completely the wrong way i.e. is this just a really bad idea? Should I rethink the UI itself?
UINavigationController *navigationController = [[UINavigationController alloc]
initWithRootViewController:addController];
[self presentModalViewController:navigationController animated:YES];
Fixed. I got the behavior I wanted by pushing the second view controller to the first view controller's UINavigationController.
creation of 1st modal view
FooAddController *addController = [FooAddController alloc]
initWithNibName:#"FooAddController" bundle:nil];
addController.delegate = self;
addController.foo = newFoo;
UINavigationController *navigationController = [[UINavigationController alloc]
initWithRootViewController:addController];
[self presentModalViewController:navigationController animated:YES];
[addController release];
creation of 2nd modal view (in FooAddController)
FooAddSizeViewController *addSizeController = [[FooAddSizeViewController alloc]
initWithNibName:#"FooAddSizeViewController" bundle:nil];
addSizeController.delegate = self;
addSizeController.foo = self.foo;
[self.navigationController pushViewController:addSizeController animated:YES];
[addSizeController release];
You need to take care on which instance you invoke the presentModalViewController when you deal with several levels of modal controllers.
Let's suppose you have :
[myControllerA presentModalViewController:myControllerB animated:YES];
Next time you want to display a modal controller while B has the focus, you should invoke
[myControllerB presentModalViewController:myControllerC animated:YES];
in order to get the parent controller properly set.
The hierarchy of controllers is then A-> B -> C
Did you try calling presentModalViewController on self.navigationControllerin both steps?