I am creating a class object from my UIViewController and trying to push a controller from it, and it won't work.
I have been doing research but found nothing, any idea?
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.newClass = [[MyNewClass alloc] init];
self.newClass.view = self.view;
self.newClass.navigationController = self.navigationController;
[self.newClass connect];
}
...
#end
MyNewClass.h
#interface MyNewClass : NSObject<UINavigationControllerDelegate>
#property(nonatomic, retain) UIView *view;
#property(nonatomic, retain) UINavigationController *navigationController;
-(void) connect;
#end
MyNewClass.m
-(void)connect
{
OtherViewController * otherVC =
[[OtherViewController alloc] init];
self.navigationController pushViewController:otherVC animated:YES];
}
...
add folloeing code into appdelegate's didFinishLaunchingWithOptions method.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self copyDatabaseIfNeeded];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
[self.window makeKeyAndVisible];
return YES;
}
and then remove all other UINavigationController declaration and allocation. Like MyNewClass's NavigationVontroller. Because here you declare and allocate navigationcontroller in appdelegate so you can use it in whole app.
When viewDidLoad is called, the view has just been loaded but the view controller hasn't necessarily been added to a navigation controller yet. So using viewDidLoad as your trigger is not useful.
A better approach is to explicitly pass the navigation controller to the view controller when it's created. Or to implement didMoveToParentViewController: and do your configuration there.
You are pushing a viewController from a controller, which is not a part of navigationController, so first make it part of navigationController, then try
Related
I want to change view by clicking button with NavigationController
So I added a button to Main.storyboard and write some codes like
#property (weak, nonatomic) IBOutlet UIButton *button;
in my ViewController.m (Created automatically when I made my project)
And I added method
- (IBAction)buttonClicked:(id)sender {
SecondViewController *secondViewController = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
[self.navigationController pushViewController:secondViewController animated:YES];
}
(I made SecondViewController.m, SecondViewController.h, SecondViewController.xib)
After this, I started the application and clicked the button but the screen didn't change.
Actually, when I added log like
NSLog(#"%#", self.navigationController);
null was printed.
I think I need to add some code about NavigationController to AppDelegate.m but I don't know what to do. Please help me.
Try This,
in Appdelegate.m
`- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController"
bundle:nil];
UINavigationController *navigation = [[UINavigationController alloc]initWithRootViewController:self.viewController];
self.window.rootViewController = navigation;
[self.window makeKeyAndVisible];
return YES;
}`
You need to embed Navigation Controller through code or Storyboard.
First select your initial viewcontroller in storyboard and embed it in NavigationController.
Then give a storyboard identifier to the second viewcontroller.
Then lastly instantiate Second ViewController from storyboard and push it.
- (IBAction)buttonClicked:(id)sender {
SecondViewController *secondViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"SecondViewController"];
[self.navigationController pushViewController:entryController animated:YES];
}
I'm creating an application that has 2 main view controllers at the moment. The app loads into the initial viewController, and clicking a button inside should bring up the second viewController. Here's what I have:
AppDelegate.h
#import <UIKit/UIKit.h>
#import "ViewController1.h"
#interface AppDelegate : UIResponder <UIApplicationDelegate>
#property (strong, nonatomic) UIWindow *window;
#property (strong, nonatomic) ViewController1 *mainViewCtr;
#property (strong, nonatomic) UINavigationController *navigationController;
#end
AppDelegate.m
- (void)applicationDidFinishLaunching:(UIApplication *)application {
_mainViewCtr = [[ViewController1 alloc] initWithNibName:#"mainViewCtr" bundle:nil];
_navigationController = [[UINavigationController alloc] initWithRootViewController:_mainViewCtr];
_window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
_window.rootViewController = _navigationController;
_navigationController.delegate = self;
_navigationController.navigationBarHidden = YES;
[_window addSubview:_navigationController.view];
[self.window makeKeyAndVisible];
}
and my button method inside viewcontroller1:
- (IBAction)SessionNickNameSubmit:(id)sender {
ViewController2 *secondViewCtrl = [[ViewController2 alloc] initWithNibName:#"secondViewCtrl" bundle:nil];
[self.navigationController pushViewController:secondViewCtrl animated:YES];
}
but when I click the button the view doesn't change. I tried debugging and the code is hit, but nothing happens.
am I missing a setting somewhere?
UPDATE
I've updated all viewController variable names:
instead of ViewController1/2 I'm using mainViewCtrl and secondViewCtrl
but still no use :(
You made a typo:
it's
_window.rootViewController = _navigationController;
not
_window.rootViewController = _joinViewController;
And NeverHopeless's suggestion is also spot on. It's probably the typo AND the fact that you add your second viewcontroller as ViewController2 and not using a proper variable name.
Another suggestion is making a storyboard (if you are not using one) and adding a segue for the transition. Simply assign the segue processing to the button. Like this:
-(IBAction)SessionNicknameSubmit:(id)sender
{
[self performSegueWithIdentifier:#"identifier" sender:self ];
}
Here is a nice description of how it works and how to use it plus some useful pointers!
Obj-C is a case sensitive language, class name and instance name should not be the same like ViewController2. Try like this:
- (IBAction)SessionNickNameSubmit:(id)sender {
ViewController2 *viewController2 = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
[self.navigationController pushViewController:viewController2 animated:YES];
}
The reason is that you have set the window's rootViewController to ViewController1.
You need to set you navigation controller to the window's rootViewController.
So that when you try to access the self.navigationController on the press of the button, it will access the navigation controller in which the self resides i.e. your window's rootViewController now.
Then it will push the next view controller properly.
After looking at almost every tutorial and every stack overflow answer, I finally found a solution that worked. I had to make an instance of the storyboard in the app delegate and use that to create my first view controller instance.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.storyboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
self.joinViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"ViewController1"];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:joinViewController];
_window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
navigationController.navigationBarHidden = YES;
_window.rootViewController = navigationController;
[_window addSubview:navigationController.view];
[self.window makeKeyAndVisible];
return YES;
}
I think the problem was that when I was creating an instance of ViewController, it was creating a new instance and binding the navigation controller to it (independent of the view controller that was showing up in the simulator). So when I was using the push method it wasn't recognizing self.NavigationController (that's why NSLog(self.NavigationController == nil) was logging 1
thank you for taking time to answer me !
I'm inexperienced in IOS development, after several searches on google, I turn to you.
My problem is that : I will wish to use UINavigationController, with new main view, to allow me to create a back button.
Here is my AppDelegate.m :
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
MainViewController *mvc = [[MainViewController alloc]init];
//self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
//UINavigationController * navController = [[UINavigationController alloc]initWithRootViewController:self.viewController];
self.window.rootViewController = mvc;
[self.window makeKeyAndVisible];
return YES;
}
and my AppDelegate.h :
#class ViewController;
#interface AppDelegate : UIResponder <UIApplicationDelegate>
#property (strong, nonatomic) UIWindow *window;
//#property (strong, nonatomic) ViewController *viewController;
#end
During development I changed the main view of the application as you can see above the two lines commented out.
I would like to use "UINavigationController" with this new main view, what does it change? and where?
Thank you and sorry if i'm not clear ! (Google Translate)
Set your MainViewController *mvc as the root of your navController and make it the root view controller of the window.
UINavigationController *navController = [[UINavigationController alloc]initWithRootViewController: mvc];
self.window.rootViewController = navController;
I have a project which I don't really understand the views and navigation behind. I start out in the AppDelegate (MAAppDelegate), where I define properties:
#property (strong, nonatomic) UIWindow *window;
#property (strong, nonatomic) UIViewController *detailViewController;
Then in the MAAppDelegate.m, I create a navigationController, and
#implementation MAAppDelegate
#synthesize detailViewController;
#synthesize window;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Init the navController for the Master Detail View of the grade cells
UINavigationController *navController = [[UINavigationController alloc] init];
detailViewController = [[UIViewController alloc] init];
UIViewController *viewController = [[MAController alloc] init];
navController = [[UINavigationController alloc] initWithRootViewController:viewController];
self.window.rootViewController = viewController;
[self.window makeKeyAndVisible];
return YES;
}
So at this point, I think I have a working naviationController, I've setup an instance of a custom UIViewController (custom class MAController) and I've set it up as the rootViewController.
Then, in my MAController class, the class where I do all of my UI stuff (the entire UI is done programmatically, no nibs or storyboards). Here is a bit of the viewDidLoad of MAController:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
[self.navigationController setNavigationBarHidden:YES]; // I commented this line out and realized it does nothing
I go on (in viewDidLoad) to add a bunch of subviews to self.view, like this
[self.view addSubview:self.backgroundImageView];
Earlier, I created a viewController in the AppDelegate class and it was called view, so I assumed it was refereeing to that but now since I've changed it (in AppDelegate) to viewController, I guess I was thinking wrong?
And then finally, I create a UIView in 'viewDidLoad`:
UIView *header = [[UIView alloc] initWithFrame:headerFrame];
header.backgroundColor = [UIColor clearColor];
self.tableView.tableHeaderView = header;
and start adding a bunch of subviews to this new UIView I created header.
So, in short, I have no idea what is happening. Later, when I tried telling (from a method inside MAController) self.navigationController (which I assumed to be navigationController in charge of everything in my project - created at the beginning in the AppDelegate) to pushViewController a new viewController that I was going to use as a detailView for a table, it got weird.
So I'm just trying to understand what has control, and what the rootViewController is, and just what is happening.
The main window root is set to a view controller and not the navigation controller
Change:
self.window.rootViewController = viewController;
to:
self.window.rootViewController = navController;
EDIT:
You can access the navigationController from anywhere by asking your appDelegate. It is normally not considered a good practice:
MAAppDelegate *delegate = (MAAppDelegate *)[[UIApplication sharedApplication] delegate];
UINavigationController *nav = delegate.navigationController;
Don't forget to:
#import "MAAppDelegate.h"
First, take a little time and read through how navigation controllers work. The documentation is really helpful:
https://developer.apple.com/library/ios/documentation/uikit/reference/UINavigationController_Class/Reference/Reference.html
Second, your problem is that your window's root view controller is not the navigation controller you created. Rather it is an instance of MAController. This is what you're doing:
UIViewController *viewController = [[MAController alloc] init];
// some other code ...
self.window.rootViewController = viewController;
I think you meant to add MAController as the root view controller of the navigation controller and make the navigation controller your window's root. If so, you'll want to set your view controllers up like this:
UIViewController *viewController = [[MAController alloc] init];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController];
self.window.rootViewController = navController;
Another potential problem is that you don't seem to be doing anything with your detailViewController. Maybe that's confusing you too.
I have one problem. in my app (it is tabbed style), I have one viewcontroller with some text and second with table view (RSS reader). When I have just the RSS and it is set to single view app, subview form rss works, but when I set up the tabbed app and click to some post in table view, subview didnt show up... Can anybody help me please?
Here are my codes:
AppDelegate.h
#import <UIKit/UIKit.h>
#interface MWFeedParserAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UINavigationController *navigationController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet UINavigationController *navigationController;
#end
AppDelegate.m
#import "MWFeedParserAppDelegate.h"
#import "ViewController1.h"
#import "RootViewController.h"
#implementation MWFeedParserAppDelegate
#synthesize window;
#synthesize navigationController;
#pragma mark -
#pragma mark Application lifecycle
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after app launch
UITabBarController *tbc = [[UITabBarController alloc]init];
ViewController1 *vc1 = [[ViewController1 alloc]init];
RootViewController *vc2 = [[RootViewController alloc]init];
[vc1.tabBarItem setTitle:#"Tab1"];
[vc2.tabBarItem setTitle:#"Tab2"];
[tbc setViewControllers:[NSArray arrayWithObjects:vc1, vc2, nil]];
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
[window setRootViewController:tbc];
return YES;
}
- (void)applicationWillTerminate:(UIApplication *)application {
// Save data if appropriate
}
#pragma mark -
#pragma mark Memory management
- (void)dealloc {
[navigationController release];
[window release];
[super dealloc];
}
#end
From the dealloc, I see you are not using arc.
You have some memory leaks; be sure to release vc1 and vc2 in your didFinishLaunchingWithOptions, the tab bar controller will retain them.
You probably don't need navigationController property, recommend you delete that until you know you'll need it.
I think you'll want to add your RSS view (vc2?) to a nav controller before adding to the tab bar controller like this:
[tbc setViewControllers:[NSArray arrayWithObjects:vc1, [[[UINavigationController alloc] initWithRootViewController:vc2] autorelease], nil]];
And delete this line:
[window addSubview:[navigationController view]];
Best of luck!!
edit Spelled out a tad more:
ViewController1 *vc1 = [[[ViewController1 alloc] init] autorelease];
RootViewController *vc2 = [[[RootViewController alloc] init] autorelease];
UINavigationController *navController = [[[UINavigationController alloc] initWithRootViewController:vc2] autorelease];
UITabBarController *tbc = [[[UITabBarController alloc] init] autorelease];
[tbc setViewControllers:#[vc1, navController]];
[window makeKeyAndVisible];
[window setRootViewController:tbc];