self.navigationController is nil after adding subview

Question

here is my productscontroller.h

ProductListViewController *productListViewController;
ProductGridViewController *productGridViewController;
UIButton *flipIndicatorButton;  

and i am adding list and gridview as a subview like this in my implementation

ProductListViewController *listController = [[ProductListViewController alloc] initWithNibName:@"ProductListView" bundle:nil];
self.productListViewController = listController;
self.productListViewController.CurrentSale = CurrentSale;
[self.view insertSubview:listController.view atIndex:0];

but in when i tried to push detailview controller from ProductListViewController.m like this

ProductDetailViewController *productDetailViewController = [[ProductDetailViewController alloc] init];

productDetailViewController.productIndexPath = indexPath;

[self.navigationController pushViewController:productDetailViewController animated:YES];

it just does not work, then i check [self.navigationController] , it was nil, now how to deal with this problem. i am ready to give some more code and detail to make more clear. thanks

September

if you're using a navigation controller, why are you inserting a subview instead of pushing views to the controller? also, is the navigation controller nil before you insert the subview as well? – Dreamworld

thanks Oren, not its not nil,let me tell how my app structure. TabBarController -NavigationControler --TableViewController ---ProductController(self.navigationControll is not null here) ----ListViewController(self.navigationControll is nil) ----GridViewControler(self.navigationControll is nil) ihope this make picture clear. – September

and i am adding flip view button as right button item, that gets added. and i can flip view, but i cant push another view control. – September

Answer 1

i found workaround for this problem. now what i am doing is i am passing ref of parent controller in this case ProductsController and written method to push next view. following this now i am calling parent method to push next view like this [parent pushNextview]; so far it works fine, hope this is good way of doing what i wanted to.

September

Answer 2

Where are you creating the Navigation Controller? At some point (probably in your App Delegate) you have to have something like this:

ProductsController *productsController = // create ProductsController
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:productsController];

And then add the navController's view as a subview to your window.

The other thing is that you appear to be using too many View Controllers for one screen. Apple recommends only one per screen.

Pragmatic

thanks bpapa, i am using only one Controller per screen, its just that i cant make view hierarchy in here. i have tabbar, and i have make first tabbar as Navigation in my Mainwindow.xib, and i am creating ProductController in BrandList controller that is my first screen , not app delegate. is this clear.if not let me know how i can make it more clear. – September

i follow this example for create subviews(i did same thing with minor change) developer.apple.com/iphone/library/samplecode/TheElements/… , hope this helps – September

Answer 3

I had the same problem recently! I "poped" ([self.navigationController popViewControllerAnimated:YES]) the viewController in the viewWillAppear: method of the viewcontroller. So I just removed this code and inserted the same code in the viewDidAppear: method and it worked!

Diversify

Answer 4

I ran into a similar issue yesterday:

Tab Bar View - Table View - View

In the table view controller, I wanted to push the "detail view" controller, but [self navigationController] was nil here. The solution was to go to this arrangement:

Tab Bar View - Navigation View - Table View - View

With the additional navigation controller, [self navigationController] now worked in the table view controller.

Transcurrent

Answer 5

I just found out why the navigationController is always nil. Your whole series of views should be contained in a UINavigationController. This means that the first view in your hierarchy will have to be your rootViewController. bpapas code should work.

Olimpia