I'm launching a view controller in my app with this code :
MyViewController *myViewController = [[MyViewController alloc] init];
[self.navigationController pushViewController:myViewController animated:YES];
However I don't know what design file my viewcontroller use to add a simple label to it. I don't know if it uses any design file(story board). I have story board file and I have assigned its class to my controller but does the above code launch the controller with the story board?
Thanks
Your myViewController does not connect to any xib file(design file)
You could connect your design file using this construct method of UIViewController.
- (instancetype)initWithNibName:(NSString *)nibName bundle:(NSBundle *)nibBundle
For example:
MyViewController *myViewController = [[MyViewController alloc] initWithNibName:#"Your_Design_File_Name" bundle:nil];
[self.navigationController pushViewController:myViewController animated:YES];
Related
I learn the ObjC program flow, so far I understand that chain begins in main.m->UIApplicationMain->AppDelegate->ViewController
The point I don't understand is to which method inside the ViewController the AppDelegate class transfers the focus...
I feel it is critical to understand this topic, so would be thankful for any clarifications.
I have this code of Appdelegate.m -
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
MasterViewController *masterViewController = [[MasterViewController alloc] init];
self.navigationController = [[UINavigationController alloc] initWithRootViewController: masterViewController];
self.window.rootViewController = self.navigationController;
[self.window makeKeyAndVisible];
return YES;
and inside the ViewController there are these methods -
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self.navigationController setNavigationBarHidden:YES animated: NO];
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear: animated];
}
and others methods...
My questions are
To what method AppDelegate transfers control in MasterViewController. And does the control come back after MasterViewController "finished" its job or it is just looped?
How MasterViewController gets the xib name for initialisation (is it the same name as m file? i.e. what does it mean - nibNameOrNil bundle:nibBundleOrNil)
I see navigation controller involvement, however I don't understand how it is connected to viewcontroller....
If you catch my misunderstanding points - please be patient to explain... I feel that after this point I will be able to start...
(1) You're thinking about the logical flow in a procedural sort of way. The main run loop dispatches events down the responder chain. Your MasterViewController doesn't really 'finish'.
(2) The designated initializer for UIViewController is initWithNibName:bundle:. Your use of init here will not touch any associated nib file. If you wish to initialize MasterViewController from the nib, then you must use the designated initializer, e.g.
MasterViewController *masterViewController = [[MasterViewController alloc] initWithNibName:#"your-nib-name-goes-here" bundle:nil];
nibNameOrNil and nibBundleOrNil are just parameter names for the method. It's a tip to you that they may be nil. Take a look at the documentation for how the method behaves when those params are nil.
(3) UINavigationController is a subclass of UIViewController that presents content hierarchically. In this case, the application's window's root view controller is a navigation controller. In turn, that navigation controller's root view controller is your MasterViewController instance.
The documentation for UINavigationController describes it well.
I have a button that open another viewController(familyView) when clicked.
In familyView there is another button which suppose to bring me back to the mainViewController(ViewController.xib) but I don't know how to call the main viewController.
My method to call familyView
UIViewController* familyView = [[UIViewController alloc] initWithNibName:#"familyView" bundle:[NSBundle mainBundle]];
[self.view addSubview:familyView.view];
I hope you could help on how to call the main ViewController ? do I have to use the same method to call it? like this I mean:
UIViewController* mainView = [[UIViewController alloc] initWithNibName:#"viewController" bundle:[NSBundle mainBundle]];
[self.view addSubview:mainView.view];
If yes, is there a better way to implement this? in my demo project, I'm trying to make 7 views full with data and a button to go back and forth.
EDIT:
If I use UIView would that be best for me instead of using different viewControllers with their implementations and interfaces files?
My project will have views, and each view has data on it parsed from a different html page.
There are two method that can be used.
UINavigationController
Delegates
From your question it seems that a UINavigationController is the best option but I will show you both.
UINavigationController
When you load your mainViewController from your app delegate your going to need to wrap it in a nav controller like so:
AppDelegate.h
#property (strong, nonatomic) UINavigationController *navController;
AppDelegate.m
#synthesize navController = _navController;
//in didFinishLaunchingWithOptions:
UIViewController *mainViewController = [[MainViewController alloc] initWithNibName:#"MainViewController" bundle:nil];
navController = [[UINavigationController alloc] initWithRootViewController:mainViewController];
self.window.rootViewController = nav1;
[self.window makeKeyAndVisible];
Now in your MainViewController you have the convince of UINavigationController.
When you want to push to a child from a parent you can simply do:
ChildViewController *child = [[ChildViewController alloc]...];
[self.navigationController pushViewController:child animated:YES];
If you in your ChildViewController and want to go back simply do:
[self.navigationController popViewControllerAnimated:YES];
This is the "Drill Down" technique.
(I know "Drill Down" has more meaning than simply that but it provides a good frame of reference.)
Delegate
Now the other method that you have is to setup delegates between the classes. So if your in childView and need to call your parent, you will have a channel to do so.
In your MainViewController.h setup it like so:
#import <UIKit/UIKit.h>
//This is our delegate
#protocol TalkToParentDelegate <NSObject>
//This is our delegate method
- (void)helloParent;
#end
#interface MainViewController : UIViewController <TalkToParentDelegate>
...
..
#end
In your MainViewController.m make sure add the delegate method.
- (void)helloParent {
NSLog(#"Hello child, let me do something here");
}
In your ChildViewController.h setup it like so:
#import <UIKit/UIKit.h>
//Add header of class where protocol was defined
#import "MainViewController.h"
#interface ChildViewController : UIViewController
//Create a property we can set to reference back to our parent
#property (strong, nonatomic) id <TalkToParentDelegate> delegate;
#end
Now, in your MainViewController.m , whenever you present your ChildViewController do this:
ChildViewController *child = [[ChildViewController alloc]...];
//Set the delegate reference to parent
child.delegate = self;
//present the view
Last but not least, no when you in your child you can call methods on your parent (MainViewController) like so:
[self.delegate helloParent];
So here are two methods that you can use.
I would like to note however, you can use these together. Say you had a UINavigationController but still needed a child to talk to its parent, you can setup a delegate so that's possible.
Hope this helps.
I am trying to call a subview after a button is clicked on my root controller. The warnings appear in my AppDelegate (code is below), but I included the method from my root controller on how I call this new subview also in case that too has a problem.
the alerts that continue to come up are that the local declaration of navController hides an instance variable.
When I launch the application (which used to open fine) it now simply exits out...
#import "SEM2REDOAppDelegate.h"
#import "SEM2REDOViewController.h"
#implementation SEM2REDOAppDelegate
#synthesize window;
#synthesize navController;
#pragma mark -
#pragma mark Application lifecycle
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[self.window makeKeyAndVisible];
SEM2REDOViewController *firstController = [[SEM2REDOViewController alloc]
initWithNibName:#"SEM2REDOViewController" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc]
initWithRootViewController:firstController];
[self setNavContorller:navController];
[window addSubview:[navController view]];
[navController release];
[firstController release];
return YES;
}
then here is the method inside of my first view controller
- (IBAction)chooseFirstMeeting:(id)sender {
SelectRotationController *selectView = [[SelectRotationController alloc]
initWithNibName:#"SelectView" bundle:[NSBundle mainBundle]];
[selectView.navigationItem setTitle:#"Select First Meeting"];
[self.navigationController pushViewController:self.selectRotationController animated:YES];
self.selectRotationController = selectView;
[selectView release];
}
I know this may be an extremely simple question but I've just started this. doing an intensive study on programming in high school as an added course so I'd really appreciate any help!
Rename navController
UINavigationController *navController = [[UINavigationController alloc]
initWithRootViewController:firstController];
into something else. You can do this automatically by control-clicking word "navController", choosing "Refactor" from context menu, and then "Rename...".
Explanation:
The problem, I believe, in your local variable navController having the same name as instance variable under synthesized declared property navController.
Edit:
Also, this seems to be a typo:
[self setNavContorller:navController];
Correct:
[self setNavController:navController];
I'm currently working on a view based app for the iPad that has 3 seperate views on the main page. A custom menu up the top, a status list on the side, and a main view. The issue I am having with the main view is trying to add a navigation controller.
In AppPadViewController.h
#interface AppPadViewController.h : UIViewController {
MainViewController *MainView;
}
#property (nonatomic,retain) IBOutlet MainViewController *MainView;
And in AppPadViewController.m
#synthesize MainView;
- (void) viewDidLoad {
[super viewDidLoad];
MainView.navigationItem.title = #"Home";
UINavigationController *mainNavController = [[UINavigationController alloc] initWithNibName:#"MainView" bundle:[NSBundle mainBundle]];
self.MainView = [MainViewController alloc] initWithRootViewController:mainNavController];
}
And in the nib I have added the view where I would like it, and tied it in to the MainView, and then added the MainViewController and tied it to the File Owner and view.
When I run this, I get an 'Unrecognized Selector" error thrown on the initWithRootViewController line.
Can anyone see any problem with the code, or suggest a better way to add a navigation controller to a sub view?
You have your two view controllers reversed. Try something like this:
self.MainView = [[MainViewController alloc] initWithNibName:#"MainView" bundle:[NSBundle mainBundle]];
UINavigationController *mainNavController = [[UINavigationController alloc] initWithRootViewController:MainView];
Does somebody know how to use the animation which is used to reveal the lower view(Map,Satellite,Hybrid, List) in the maps application?
You have to create a new ViewController
Eg:
MyViewController *myvc = [[MyViewController alloc] initWithNibName: #"blablabla"];
[self presentModalViewCOntroller: myvc animated: YES];
Giving that MyViewController is a subclass of UIViewController for example and this i run from another viewcontroller.