When I built Presence 2, I made a fairly significant mistake that has now cost me a lot of time. I instantiated both a UINavigationController and a custom TableViewController in my app delegate, but I didn't push my TableViewController onto the stack of views that are managed by my UINavigationController. Instead, this is what I did: - (void)applicationDidFinishLaunching:(UIApplication *)application { personListViewController = [[PersonListViewController alloc] initWithStyle:UITableViewStylePlain]; personListViewController.view.frame = [UIScreen mainScreen].applicationFrame; [window addSubview:personListViewController.view]; navigationController = [[UINavigationController alloc] initWithRootViewController:personListViewController]; [window addSubview:navigationController.view]; [window makeKeyAndVisible]; } Well, that is wrong. Pragmatically, it seemed to work, except that by the time I started Presence 3 I discovered that in my TableViewController implementation, this was causing problems; not the least of which was that on initial load, viewWillAppear in my TableViewController's implementation was being called twice. Since I was using viewWillAppear to call a method that would instantiate a NSInvocationOperation and add it to an NSOperationQueue, it was causing some problems. Okay so lesson learned (twice). In order to add a UITableViewController to a UINavigationView, you need to push the UITableViewController's view onto the stack of views managed by the UINavigationView. Here's the correct code: - (void)applicationDidFinishLaunching:(UIApplication *)application { navigationController = [[UINavigationController alloc] init]; personListViewController = [[PersonListViewController alloc] initWithStyle:UITableViewStylePlain]; [navigationController pushViewController:personListViewController animated:NO]; [window addSubview:navigationController.view]; [window makeKeyAndVisible]; } |
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Reviewing UINavigationControllerposted Dec 7, 2009 7:50 AM by Theresa McClain |