I wish to place a screen before my curren RootViewController. So far I have made the following modification to MyAppDelegate:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//with this in the existing RootViewController loads correctly
//self.window.rootViewController = self.navigationController;
self.window.rootViewController = [[[HomePageController alloc] init] autorelease];
}
I'm not entirely sure how self.navigationController actually gets set to my RootViewController. Either way if I make the modification my HomePageController does load correctly, however I am then unable to push another view on top of it. I have a simple button on HomePageController that performs the following (note that HomePageController should load the currently named RootViewController, HomePageController is the view I want to sit above this):
RootViewController *rvC = [[[RootViewController alloc] initWithNibName:#"RootViewController" bundle:[NSBundle mainBundle]] autorelease];
[self.navigationController pushViewController:rvC animated:YES];
When this code runs nothing happens... I'm not entirely sure why, possibly something related to the navigationController? Maybe I havent put HomePageController above RootViewController correctly or in the best way?
You have no navgiationController currently installed.
To fix you have to replace
self.window.rootViewController = [[[HomePageController alloc] init] autorelease];
with
self.window.rootViewController = [[[UINavigatoinController alloc] initWithRootViewController:[[[HomePageController alloc] init] autorelease]] autorelease];
now you have navigationController installed and following
[self.navigationController pushViewController:rvC animated:YES];
will do the right job.
Related
I'm creating a tabbed iPhone application. When the application launches, if the user is not logged in, a modal view is supposed to be presented over the top of the tab bar controller (so it looks like this is the first screen). Upon login the modal view slides away to reveal the tab bar controller behind it.
Unfortunately when I call [self.tabBarController presentViewController:self.loginViewController animated:NO completion:NULL] from inside my application delegate I can still see the tabs along the bottom of the screen. I need them covered.
Ironically when searching for a solution, I find most people are having the inverse problem.
I have noticed that if I don't set my window's rootViewController to the UITabBarController, only inserting its view as a subview of the window, then it works as expected, but Xcode complains about the lack of rootViewController. What's going on here?
My application delegate's -application:didFinishLaunchingWithOptions: method looks like this.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self registerDefaults];
self.tabBarController = [[[UITabBarController alloc] init] autorelease];
self.tabBarController.viewControllers = #[
[self makeSellingListingsController],
[[[UIViewController alloc] init] autorelease], // stub
[[[UIViewController alloc] init] autorelease], // stub
[[[UIViewController alloc] init] autorelease] // stub
];
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
self.window.rootViewController = self.tabBarController;
[self.window addSubview:self.tabBarController.view];
[self presentLogin]; // this doesn't cover the tabs, but it should
[self.window makeKeyAndVisible];
return YES;
}
- (void)presentLogin
{
[self.tabBarController presentViewController:[[[FLLoginViewController alloc]
initWithNibName:#"FLLoginViewController"
bundle:[NSBundle mainBundle]] autorelease]
animated:NO
completion:NULL];
}
Don't present it from the tab bar controller, but from the root controller in the first tab, in its viewDidAppear method. If you pass NO to the animation parameter, the modal screen will be the first thing you see when you start the app.
The code I am using
NSLog(#"before Navigate to second activity");
Signature *temp = [[Signature alloc]initWithNibName:#"Signature" bundle:nil];
[self.navigationController pushViewController:temp animated:YES];
NSLog(#"after Navigate to second activity");
On console,both the log statements are getting printed, but my app is not navigating me to the next View.Please correct me.
if you are not using a UINavigationController on your app you can not call pushViewController, use presentViewController:animated:completion: instead:
[self presentViewController:temp animated:YES completion:nil];
for more information check the documentation
The log messages would show anyway, so no surprise there. Add a callback to the delegate for that navigation controller (you must first set a delegate of course) for
navigationController:didShowViewController:animated:
There you can make sure that the viewController passed (make sure Signature is a ViewController instance).
i think your application is not with navigationController so in AppDelegate.m file assign rootViewController like this..
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
RootViewController *viewController1 = [[[RootViewController alloc] initWithNibName:#"RootViewController" bundle:nil] autorelease];
UINavigationController *navviewController=[[UINavigationController alloc]initWithRootViewController:viewController1];
self.window.rootViewController = navviewController;
[self.window makeKeyAndVisible];
return YES;
}
after that check its working..
CreditsViewController *viewController = [[CreditsViewController alloc] init];
[[self navigationController] pushViewController:viewController animated:YES];
[viewController release];
you can try with above code
I'm having trouble coding a button to go to the previous page. I was able to do it to go to the next page thinking if I did the same thing but changed it a bit it would work in reverse. Unfortunately, I come up with a lot of errors I can't resolve because it won't allow me to use the release function.
This is this the code that helps it to work going to the next page fine:
#import "ViewController.h"
#implementation ViewController
-(IBAction)btnClicked:(id) sender
{
//add the view of the view controller to the current View---
if (menuView==nil) {
menuView =
[[MenuView alloc] initWithNibName:#"MenuView"
bundle:nil];
}
[self.view addSubview:menuView.view];
}
-(void)dealloc {
[menuView release];
[super dealloc];
}
How do I do it so that a back button will go to the previous page though.
It's pretty simple, use this :
-(IBAction)back:(id) sender
{
[menuView.view removeFromSuperview];
}
But, I would suggest not using addSubview: for many views as it would be complex way to do. Use UINavigationController as #Paul.s suggested.
The way you are doing this is not quite correct and I would suggest doing some reading to get familiar with iOS programming.
Your program structure should be: create a navigation controller (2) to manage the stack of view controllers giving it a viewController (1) to act as it's root.
// AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
// 1
FirstViewController *firstViewController = [[FirstViewController alloc] init];
// 2
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:firstViewController];
[firstViewController release]; firstViewController = nil;
self.window.rootViewController = navigationController;
[navigationController release]; navigationController = nil;
[self.window makeKeyAndVisible];
return YES;
}
This will display your first view controller inside a UINavigationController. A UINavigationController is responsible for managing a stack of UIViewController's and giving you UI to navigate back down the stack as well as calling all the appropriate presentation related methods on a UIViewController at the correct times e.g. viewDidLoad. You should check out The View Controller Programming Guide for lots of info
Then inside your first view controller you do something like this to respond to the button:
- (IBAction)buttonClicked:(id)sender;
{
SecondViewController *secondViewController = [[SecondViewController alloc] init];
[self.navigationController pushViewController:secondViewController animated:YES];
[secondViewController release]; secondViewController = nil;
}
This creates a new view controller and pushes it onto the stack.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
// Add the view controller's view to the window and display.
[window addSubview:viewController.view];
MainPageDialog *overviewViewController = [[MainPageDialog alloc] initWithNibName:#"MainPage" bundle:nil];
UINavigationController *nav_obj = [[UINavigationController alloc] initWithRootViewController:overviewViewController ];
[self.viewController presentModalViewController:nav_obj animated:YES];
[overviewViewController release];
[self.window makeKeyAndVisible];
return YES;
}
This code shows the blue bar of navigation controller, but no buttons on it.It seems like to be that the UINavigationController allocated as empty.
Who knows what problems is?
UPD:Archive http://www.mediafire.com/?lbjjvl6fcue2q18
Please help me, I'm new in objective-c
You need to create the button for it, for example:
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:launcherView action:#selector(endEditing)];
self.navigationItem.leftBarButtonItem = doneButton;
[doneButton release];
The correct way to use a UINavigationController is to push view controllers on to it. That way they will be stacked and the navigation bar will be populated with a back button when it is case (i.e., when you can actually go back to a previous controller). You control the label that appears in the "back" button by defining the title of the controllers you push.
The technique shown in another answer (setting explicitly the button) is useful with defining the right button, if you ever need one.
You could try with this code:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
MainPageDialog *overviewViewController = [[MainPageDialog alloc] initWithNibName:#"MainPage" bundle:nil];
UINavigationController* navigation = [[UINavigationController alloc] init];
[navigation pushViewController:overviewViewController animated:NO];
[overviewViewController release];
[window addSubview:[navigation view]];
[self.window makeKeyAndVisible];
return YES;
}
Instead of doing:
UINavigationController* navigation = [[UINavigationController alloc] init];
[navigation pushViewController:overviewViewController animated:NO];
you could also use initWithRootController, but to display the general case of how you push a view controller I preferred this one.
Notice that since you are pushing just a root controller, you should see no back button at the moment, but if you push a second view controller, then it will appear.
EDIT: I gave a look at your project. Summary of what you should try and do:
objects you need in your NIB: File's Owner (UIApplication), First Responder, FBFun App Delegate (iVkAppDelegate), Window (UIWindow); remove the rest;
File's owner delegate outlet is FBFun App Delegate;
FBFun App Delegate window outlet is Window.
With this simple setup (more or less what you have), use this code :
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
UINavigationController* navigation = [[UINavigationController alloc] init];
//-- MainPageDialog *overviewViewController = [[MainPageDialog alloc] initWithNibName:#"MainPage" bundle:nil];
iVkViewController *overviewViewController = [[iVkViewController alloc] init];
overviewViewController.title = #"First";
[navigation pushViewController:overviewViewController animated:NO];
iVkViewController *overviewViewController2 = [[iVkViewController alloc] init];
overviewViewController2.title = #"Second";
[navigation pushViewController:overviewViewController2 animated:NO];
[overviewViewController release];
[window addSubview:[navigation view]];
[self.window makeKeyAndVisible];
return YES;
}
In the code above, as you notice, I instantiated twice your iVkViewController just to have a second controller to push onto the navigator.
Please, delete your existing app from the simulator, and the run this in order to see that the navigation bar is correctly created and you can go back from the second controller to the first one.
I removed usage of MainPageDialog, because the MainPage nib has many problems.
But I hope this skeleton is sufficient for you to go forward with your development.
You had missed the line as you are not adding view to window.Add this line in your code
[window addSubview:nav_obj.view];
How do I add an existing UIViewController (which is presented using presentModalViewController) to a UINavigationController?
When user tap on button, a new copy of my detail view need to be pushed. (In other words, pushViewController displaying pushViewController, modally, in a UINavigationController).
Easiest way to enable this functionality?
how do you create your modal viewcontroller? Just wrap the controller into a UINavigationController
Let's assume your modal code is like this:
MyExampleViewController *vc = [[[MyExampleViewController alloc] initWithNibName:#"MyExample" bundle:nil] autorelease];
[self presentModalViewController:vc animated:YES];
Then change it into something like this:
MyExampleViewController *vc = [[[MyExampleViewController alloc] initWithNibName:#"MyExample" bundle:nil] autorelease];
UINavigationController *navController = [[[UINavigationController alloc] initWithRootViewController:vc] autorelease];
[self presentModalViewController:navController animated:YES];
I think you need to add a navigation controller in your delegate, after that you can push the view. So that you can push the view from anywhere in your application.
on AppDelegate.h
UINavigationController *navig;
on AppDelegate.M
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
navig = [[UINavigationController alloc] initwithRootViewController:viewController.view];
//[navig pushViewController:viewController animated:YES];
[self.window addSubview:navig.view];
[self.window makeKeyAndVisible];
return YES;
}