I'm pushing a UIViewController like so:
UIViewController* individualsController = [[[UIViewController alloc] initWithNibName:#"IndividualsController" bundle:nil] autorelease];
[self.navigationController pushViewController:individualsController animated:YES];
The NIB itself is loading fine, all the elements load on the screen. BUT none of the view controller's methods are getting called. No viewDidLoad, no viewWillAppear, just a pushed NIB with nothing else.
The view outlet is set up in the NIB; I can't figure out why none of it is getting called!
One possibility is that you are instantiating it as a UIViewController rather than the name of your UIViewController subclass, so it is calling those methods, but on UIViewController, not on your class. Assuming that the subclass is called IndividualsController, try changing the line to
IndividualsController* individualsController = [[[IndividualsController alloc] initWithNibName:#"IndividualsController" bundle:nil] autorelease];
and see what happens.
Related
In my app I've added a label to a view, connected it to an outlet but nothing shows up when I first assign this outlet from another view controller and then call pushViewController to display it. Here's the code before pushing next view that display the label:
CustomViewController *vc = [[CustomViewController alloc] init];
vc.lbl_price.text = self.label_price.text; // lbl_price is defined as a property in CustomViewController and label_price is defined in current view controller
[self.navigationController pushViewController:vc];
In the CustomViewController viewDidLoad method I added this instruction to see if it should work
NSLog(#"Price=%#",lbl_price); // it actually prints out what was previously assigned
But it doesn't show into the label!
Any idea why ?
Stephane
Even if view controller is created its view hierarchy may not (and so all subviews will still be nil), for optimization reasons it may not be loaded until you try to actually access controller's view. You have two options to solve your problem:
Store all values in separate non-UI variables and assign them to UI components with controller is going to appear:
// Before push controller
vc.myPriceText = self.label_price.text;
// In controller's viewWillAppear:
self.lbl_price.text = self.myPriceText;
Make [vc view] call to force controller to load its view hierarchy:
CustomViewController *vc = [[CustomViewController alloc] init];
[vc view];
vc.lbl_price.text = self.label_price.text;
[self.navigationController pushViewController:vc];
I want to setup a UIViewController within a NavigationController programmatically, however the loadView nor viewDidLoad method get called.
This is my code in the app delegate:
MyViewController *viewController = [[MyViewController alloc] init];
UIView *view = [[UIView alloc] initWithFrame:window.frame];
viewController.view = view;
UINavgationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController];
[window addSubview:[navController view];
[window makeKeyAndVisible];
When I start the app I see a navigationbar, but no calls to loadView. What am I missing?
I thought loadView gets called after you call view
Edit
MyViewController *viewController = [[MyViewController alloc] init];
[viewController view]; // doesn't look right?
UINavgationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController];
[window addSubview:[navController view];
[window makeKeyAndVisible];
edited towards Jonah's comment, but loadView still doesn't get called.
A UIViewController will create its view (by loading it from a nib or implementing -loadView) when the controller's view getter is called and its view is currently nil.
In the code shown you never invoke the view property's getter, only its setter.
Also, you are assigning the controller's view from your app delegate. UIViewControllers are expected to create their own views on demand, not have them provided by some other class. This approach will cause you problems later when you realize that the controller unloads its view and attempts to recreate it in response to memory warnings. Let your controller create its view, don't try to pass it one.
maybe you were not facing this issue... but the other day I ran into the same irritating trouble.. loadView, viewDidLoad and viewWillAppear not being called in my UIViewController.
My issue was v. simple but bit tricky to catch if you are not very careful. Instead of writing
-(void) loadView
I wrote:
-(void) loadview
Please note that this won't fire any warning. The difference of "V" and "v" in loadView can easily be missed. And obviously, since loadView didn't get called, viewDidLoad/viewWillAppear won't get called either as there was no view that got loaded (am not using any nib..creating the view programmatically).
-Anshu
Another gotcha worth noting is if you define a
#synthesize view;
without a matching #property in your implementation, this can result in calls to your view controller's returning nil, and no call to your loadView method.
I have a View application with a Single UIViewController. I then add a UITableViewController through the IB, and I am trying to display the UITableViewController through a button press in the UIViewController (my main view). My button press (IBAction) contains the following code through which I am trying to push my UITableViewController view and display it:
DataViewController *dataController = [[DataViewController alloc] initWithNibName: #"DataViewController" bundle:nil];
[self.navigationController pushViewController:dataController animated:YES];
[dataController release];
My DataViewController is not at all getting pushed into the stack and displayed,
Also I have checked that in the code above, self.navigationController=nil
Probably this is the source of the problem. If so, how to rectify it?
Please help.
UINavigationController *navCtrlr = [[UINavigationController alloc]initWithRootViewController:yourfirstviewController];
[self.window setRootViewController:navCtrlr];
navCtrlr.delegate = self;
navCtrlr.navigationBarHidden = YES;
Create navigation controller in appdelegate.m then you can navigate to any uiviewcontroller
You need to actually create a UINavigationController. The navigationController property tells you whether your DataViewController is currently in a UINavigationController's hierarchy; if not (as in this case), the navigationController property returns nil.
This one make me go crazy. I am building an iphone app where the first view is a login view. UIViewController, when the user succesfully logs in i want to display i table view. Somehow i just have big problems doing this.
In my app delegate i load my loginViewController, and then i want from the loginViewController load my listViewController.
What is the logic behind switching to a UITableViewController from a UIViewController?
you'd better to do it in your app delegate and surely NOT add the UITableViewController.view to the UIViewController.view... just add it to the UIWindow and then dismiss the old UIViewController (removeFromSuperView it's view and then release it)
EDIT:
that's how i manage:
i add a method in my appDelegate:
-(void)switchMainView;
and from my UIViewController i just call it with this:
[[[UIApplication sharedApplication] delegate] switchMainView];
in switchMainView i just
remove my UIViewController.view from superview,
release UIViewController,
alloc the UITableViewController and init it, then
add its view to the window app:
-(void)switchMainView{
if (mainView!=nil){ // mainView is the UIViewController
[mainView.view removeFromSuperview];
[mainView release];
mainView = nil;
}
Menu *vc; // Menu is my class, subClass of a UITableViewController
vc = [[Menu alloc] init];
nc = [[UINavigationController alloc] initWithRootViewController:vc];
[window addSubview:nc.view];
[vc release];
}
and then i do the same for going back, eventually
Assuming you already have your custom UITableViewController created:
YourTableViewController *vc = [[UITableViewController alloc] initWithStyle:...];
[self presentModalViewController:vc animated:YES];
[vc release];
you can use either i do'nt think there is a major impact but definitely they might have some advantage/Disadvantage over other..
for better understanding read the below tutorial.
http://cocoawithlove.com/2009/03/recreating-uitableviewcontroller-to.html
I have a custom viewController called SourceListViewController, and I'm adding it into a UINavigationController, the view of which is then added to the window of the iphone App. After passing the SourceListViewController to UINavigationController, I release the sourceListViewController.
SourceListViewController *sourceListVC = [[SourceListViewController alloc] initWithNibName:#"SourceListViewController" bundle:nil];
UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:sourceListVC] autorelease];
[sourceListVC release];
When I do this, the app would crash after the view is loaded onto the phone. When I commented out the last line, the app work fine. Isn't initWithRootViewController supposed to retain the copy of sourceListVC?
You are autoreleasing navigationController. So if navigationController gets autoreleased (which will probably happen in the next runloop) then so will sourceListVC.