I want to ask a question about the iPhone application. In my program, there are several controller class. However, I dont' know how to handle them and switch the control right between different view controller classes. I read some code from the apple website. Can anyone explain to me? Thank you very much.
// I create a view controller called 'MyViewController'
- (void)applicationDidFinishLaunching:(UIApplication *)application {
NSLog(#"applicationDidFinishLaunching");
MyViewController *aViewController = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:[NSBundle mainBundle]]; // what meaning of this statement
[self setMyViewController:aViewController]; // can I set in other class
[aViewController release];
UIView *controllersView = [myViewController view]; // what is it use?
[window addSubview:controllersView];
// Override point for customization after application launch
[window makeKeyAndVisible];
}
// what meaning of this statement
MyViewController *aViewController = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:[NSBundle mainBundle]];
This block will load your main view controller from the .xib file. Do you know about Interface Builder, you can set the View of the ViewController in the MyViewController.xib and then load it using this line
[self setMyViewController:aViewController]; // can I set in other class
Theoretically, you can set a ViewController in anywhere you have viewControlelr as a property. However, the code here means that you set the aViewController as your root view controller in the program, the first view controller you will see when you open the program.
UIView *controllersView = [myViewController view]; // what is it use?
[window addSubview:controllersView];
These 2 lines will make the view visible and can be seen by the user. you add the subview of your root view controller into the main window, and then show it
Related
When I push cancel button in the third view, I want to go back to the first view directly.
I also want to remove the second view.
How can I do that?
This is the code.
// this part is in the first view.
self.second = [SecondController alloc] init];
[self.view addSubview:second.view];
// this part is in the second view.
ThirdController *thirdController = [[ThirdController alloc] initWithStyle:UITableViewStyleGrouped];
self.navigationController = [UINavigationController alloc] initWithRootViewController:thirdController];
[self.view addSubview:navigationController.view];
// this part is in the third view.
- (void)cancel {
[self.view removeFromSuperview]; // this only goes to the second view.
}
EDIT:
Can I use popToViewController in called contoller? My app crashes.
I thought popToViewController can be used only in calling controller.
And popToViewController is used when it was pushed.
I did add not push.
[self.navigationController popToViewController:[[self.navigationController viewControllers] objectAtIndex:0] animated:YES];
popToViewController:animated: is a UINavigationController method that you use when popping view controllers off the navigation controller stack. It doesn't fit for this scenario.
This user is adding subviews, not pushing them on a navigation controller stack.
As a note, it appears as a matter of design you should be using a navigation controller with the first view as the root controller, then the second pushed on the stack, and the third pushed on the stack. Then all you have to do is [self.navigationController popToRootViewControllerAnimated:YES].
I think this will work if you want to keep your current architecture:
// this part is in the third view.
- (void)cancel {
// remove the second view (self.view.superview) from the first view
[self.view.superview removeFromSuperView];
// can't recall, possibly you still need to remove the third view, but i think removing the superview will do it.
// [self.view removeFromSuperView];
}
If you prefer to try the UINavigationController route, then the easiest path is to create a new project in Xcode and select the type for a Navigation-Based Application or a Master-Detail Application. This will create a UINavigationController in a nib and add it to your window. You can then set the root view controller in Interface Builder to your FirstViewController class.
If you prefer to create the UINavigationController in code, then that is also possible. I show that below, along with the rest of the code you need, regardless of whether you create your UINavigationController in a nib in IB or in code.
I also recommend reading the View Controller Programming Guide for iOS.
In your app delegate or some other code:
-(void)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions [
// I would recommend setting up the UINavigationController and FirstViewController as IBOutlets in your nib, but it can be done in code.
FirstViewController* fvc = [[FirstViewController alloc] initWithNibName:#"FirstView" bundle:nil];
UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:fvc];
[window addSubView:navController.view];
[window makeKeyAndVisible];
[fvc release];
[navController release];
}
In the first view controller:
SecondViewController* svc = [[SecondViewController alloc] initWithNibName:#"SecondView" bundle:nil];
[self.navigationController pushViewController:svc animated:YES];
[svc release];
In the second view controller:
ThirdViewController* tvc = [[ThirdViewController alloc] initWithNibName:#"ThirdView" bundle:nil];
[self.navigationController pushViewController:tvc animated:YES];
[tvc release];
In the third view controller:
-(void)cancel {
// returns to the first view controller
[self.navigationController popToRootViewControllerAnimated:YES];
}
Use
- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated
to go back to a specific view controller.
Try this:
[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1] animated:YES];
This will pop to the view at index 1. Hope that Helps!
// this part is in the third view.
- (void)cancel {
self.first = [SecondController alloc] init];
[self.view addSubview:second.view];
}
And I think if you have you don't need to be worried about removing beneath view, later these will removed.
I'm making an iphone app out of the utility template in xcode. So in my FlispSideView I have a button that should show a custom image picker. I decided to use this nice one here link.
Now I made some changes cuz I'm not using a navigation controller to load the custom image picker (but rather modally) which is created programmatically inside the .m file. So I made the FlipSideView the delegate for the custom image picker but still lost when I come to loading the view. I created a xib file and tried to connect it to the image picker but that didn't work.
So I wonder what's the best way to do that?
I'm not sure I interpreted your question correctly, but based on the title, I think this might be what you are looking for:
// Initialize your custom controller and set the delegate
UIViewController *controller = [[UIViewController alloc] initWithNibName:#"MyView" bundle:nil];
controller.delegate = self;
// Set the title of your custom controller (optional)
controller.title = NSLocalizedString(#"My View", nil);
// Create a navigation controller with your custom controller as the root view controller
UINavigationController *navCon = [[UINavigationController alloc] initWithRootViewController:controller];
// Present the navigation controller as a modal view controller
[self.navigationController presentModalViewController:navCon animated:YES];
// Release objects you own
[navCon release];
[controller release];
If your image picker is a controller, and all the outlets on your xib are properly connected to it, this should work. You should be able to make your FlipSideView the delegate. Pressing cancel or done in the modal view should call a message in the delegate that says
[self.navigationController dismissModalViewControllerAnimated:YES];
EDIT:
Here is the first line of my example code updated to match the tutorial you are using:
CustomImagePicker *controller = [[CustomImagePicker alloc] init];
The rest is the same. You initialize a navigation controller with controller as the root view controller, then present the navigation controller as a modal view controller.
Creating navigation programatically
Use the code below to navigate programatically. Write the following code in
AppDelegate.m class
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
FirstViewController *firstViewController = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
self.nav = [[UINavigationController alloc] initWithRootViewController:firstViewController];
[_window addSubview:nav.view];
[_window makeKeyAndVisible];
}
I have created a view based application and in the appdelegate .h file I have created UINavigationcontroller object and added it to window subview. Next in the app did finish launching I had allocated and initialised a class that I want to be viewed when the app first launches with the navigation bar on the top of it.
So this is the code I have did to add the class to navigation bar
- (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:navController.view];
//test is the class that i want to be viewed first when the app launches first
test *t = [[test alloc]initWithNibName:#"test" bundle:nil];
[navController.view addSubview:t.view];
[window makeKeyAndVisible];
return YES;
}
but the problem is my test class launches but it does not display the navigation bar. What may be the problem?
Use some like this (add these lines)
appDelegate.h
UINavigationController *navController
#property (nonatomic,retain) UINavigationController *navController;
and in .m
test *t = [[test alloc]initWithNibName:#"test" bundle:nil];
self.navController=[[[UINavigationController alloc] initWithRootViewController:t] autorelease];
[window addSubview:self.navController.view];
[window makeKeyAndVisible];
it helps you.
From other view you need to make object of the appDelegate class then access the navigation controller of that class
see this
yourAppDelegateClass *objAppDelegate=(yourAppDelegateClass *)[[UIApplication sharedApplication] delegate];
now for pushing a view
SecondView *s=[[[SecondView alloc] initWithNibName:#"yournibName" bundle:nil] autorelease];
[objAppDelegate.navController pushViewController:s animated:YES];
this concept help you.
You shouldn't add your own view controller's view as a subview of the navigation controller. This way, you hide the navigation controller's view (including the navigation bar) and it makes the navigation controller pointless, because it doesn't know that your view controller wants to be part of its navigation stack.
Instead, push it on the navigation controller's stack by using:
[navController pushViewController:myViewController animated:NO];
Navigation bar is not coming because you are setting navigation controller's view to your test view. You can do it by setting navigation controller's view controllers which requires an array as -
test *t = [[test alloc]initWithNibName:#"test" bundle:nil];
NSArray *viewControllers = [[NSArray alloc] initWithObjects:t,nil];
[self.navigationController setViewControllers:viewControllers];
First, I don't see where you alloc init your navController. Secondly, you don't add a viewController to a navigation controllers view, rather you push the view controller onto the stack, like this:
[navController pushViewController:t animated:NO];
Hope this helps.
I have the following code and I want to load the UIViewController. How can I initialize and load the UIViewController.
- (void) applicationDidFinishLaunching:(UIApplication*)application
{
CC_DIRECTOR_INIT();
NSLog(#"applicationDidFinishLaunching");
MainViewController *controller = [[MainViewController alloc] init];
}
From your delegate you can do this (assuming you have IBOutlet UIWindow *window):
[window addSubview:[controller view]];
[window makeKeyAndVisible];
Once a controller is loaded, you can push others (from the UIViewController):
controller = [[MainViewController alloc] init];
[[self navigationController] pushViewController:controller animated:YES];
Here is a link to the documentation for UINavigationController.pushViewController
http://developer.apple.com/library/ios/documentation/UIKit/Reference/UINavigationController_Class/Reference/Reference.html#//apple_ref/occ/instm/UINavigationController/pushViewController:animated:
TestViewController *testController = [[TestViewController alloc] init];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window setRootViewController:testController];
[self.window makeKeyAndVisible];
Although adding a subview will work fine, you will receive the following warning unless you set your controller as RootViewController:
Application windows are expected to have a root view controller at the
end of application launch
Are you using a nib file to set up the user interface of your view? The code you currently have does load and initialize the ViewController. But you would then need to add some user interface elements to your view, and present that view controller in your application. If you arre using a nib file for your user interface, then you want:
MainViewController *controller = [[MainViewController alloc] initWithNibName:#"nibFileName" bundle:nil];
This will associate your controller with the nib file. If you are not using a nib file, you need to programmatically add each element that you wish to display.
After your view is set up, you then need to present the view controller, by either adding it as a subview to your current view, or using a navigationController to push the new viewController. You need to be more specific about exactly what you are trying to do.
I think what you want to add is:
[[NSBundle mainBundle] loadNibNamed:#"nibWithMainViewControllerAsOwner" owner:controller options:nil];
loadNibNamed:owner:options: is the only method added to NSBundle by UIKit. See NSBundle UIKit Additions Reference. And if there's any problem with outlets not being wired up correctly then check all your outlets are key-value coding compliant (alternative answer: make sure they're correctly exposed as properties).
[viewController view]
That's how to load viewController. When the view is accessed it's lazy loaded.
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 ...