Unable to pushViewController for subview

Question

I have a UINavigationController and I have seperate UIViews that I switch between using a UISegmentControl. On switching the views, I add the view as a subview to my navigation controller's view:

[self.view addSubview:segmentTab1.view];

and

[self.view addSubview:segmentTab2.view];

Then, in the subViews, each has a UITableView, but my issue is, that I am unable to push a new viewController into view in the didSelectRowAtIndexPath method.

The method is called correctly and by setting breakpoints, I can see the method for pushing the view gets called as well, but nothing happens. This is my code for pushing it:

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

I also tried

[super.navigationController pushViewController:detailsViewController animated:YES];

What am I doing wrong - or is is just not possible to do it with a subview?

Answer 1

When you call -pushViewController, which view controller is self? If you are calling that from within one of your tab subviews, self likely doesn't have a reference to the navigation controller from the top level view that you added it to. You can verify this by getting the memory address of the navigation controller from within the top level view and comparing it to what you have in the subview. Obviously if it's nil or doesn't match, then that's your problem.

You only get a navigation controller "for free" when it's been added to the navigation stack itself with -pushViewController which your subviews haven't been added that way.

Answer 2

It is not entirely clear to me what your view hierarchy is, but in general if your navigation controllers view is not the first subview of a window or an element of one of Apple's collection views (either another navigation view controller's content view or a tab controller's content view) it won't work correctly.

Answer 3

Instead of

[self.view addSubview:segmentTab1.view];

and

[self.view addSubview:segmentTab2.view];

you may use

[self pushViewController: segmentTab1 animated: NO];

and

[self pushViewController: segmentTab2 animated: NO];

to add your viewControllers to the navigation hierarchy, and make [super.navigationController pushViewController:detailsViewController animated:YES]; work.

Answer 4

One possibility, if you are not averse to singletons, is to make your product's UINavigationController object be a singleton, accessible from (for example) your application delegate.

You would invoke it thus:

[[((MyApplicationDelegate*)[UIApplication delegate]) navController] 
                pushViewController: viewControllerToPush animated: YES];

where within MyApplicationDelegate, navController returns the singleton object.

Answer 5

Hey everyone. I am having the exact same issue. I followed instructions from this video: http://www.youtube.com/watch?v=LBnPfAtswgw&feature=player%5Fembedded#. I changed some things around to make it work with what I am trying to accomplish but the underlying logic I left the same. She is working with SDK 2.* and I am using 3.*. I assume this has something to do with it. Can anyone help me out? This is what my didSelectRowAtIndexPath looks like :

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    // Navigation logic may go here. Create and push another view controller.
    NSInteger row = [indexPath row];
    if(self.detailViewController == nil) {
     LogEntryDetailViewController *logEntryDetail = [[LogEntryDetailViewController alloc]
                 initWithNibName:@"LogEntryDetailView" bundle:[NSBundle mainBundle]];
     self.detailViewController = logEntryDetail;
     [logEntryDetail release];
    }

    detailViewController.title = [NSString stringWithFormat:@"%@", [logEntriesArray objectAtIndex:row]];

    ProgNameAppDelegate *delegate = (ProgNameAppDelegate *)[[UIApplication sharedApplication] delegate];
    [delegate.logViewNavController pushViewController:self.detailViewController animated:YES];
}

I am going nuts here. If I need to post this somewhere else I will be happy to do so. Thanks in advance!