iPad keyboard will not dismiss if modal ViewController presentation style is UIModalPresentationFormSheet

Question

Note:

See accepted answer (not top voted one) for solution as of iOS 4.3.

This question is about a behavior discovered in the iPad keyboard, where it refuses to be dismissed if shown in a modal dialog with a navigation controller.

Basically, if I present the navigation controller with the following line as below:

navigationController.modalPresentationStyle = UIModalPresentationFormSheet;

The keyboard refuses to be dismissed. If I comment out this line, the keyboard goes away fine.

...

I've got two textFields, username and password; username has a Next button and password has a Done button. The keyboard won't go away if I present this in a modal navigation controller.

WORKS

broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil];
[self.view addSubview:b.view];

DOES NOT WORK

broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil];
UINavigationController *navigationController = 
[[UINavigationController alloc]
 initWithRootViewController:b];
navigationController.modalPresentationStyle = UIModalPresentationFormSheet;
navigationController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:navigationController animated:YES];
[navigationController release];
[b release];

If I remove the navigation controller part and present 'b' as a modal view controller by itself, it works. Is the navigation controller the problem?

WORKS

broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil];
b.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:b animated:YES];
[b release];

WORKS

broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil];
UINavigationController *navigationController = 
    [[UINavigationController alloc]
         initWithRootViewController:b];
[self presentModalViewController:navigationController animated:YES];
[navigationController release];
[b release];

Answer 1

This has been classified as "works as intended" by Apple engineers. I filed a bug for this a while back. Their reasoning is that the user is often going to be entering data in a modal form so they are trying to be "helpful" and keep the keyboard visible where ordinarily various transitions within the modal view can cause the keyboard to show/hide repeatedly.

edit: here is the response of an Apple engineer on the developer forums:

Was your view by any chance presented with the UIModalPresentationFormSheet style? To avoid frequent in-and-out animations, the keyboard will sometimes remain on-screen even when there is no first responder. This is not a bug.

This is giving a lot of people problems (myself included) but at the moment there doesn't seem to be a way to work around it.

UPDATE:

In iOS 4.3 and later, you can now implement `-disablesAutomaticKeyboardDismissal' on your view controller to return NO:

- (BOOL)disablesAutomaticKeyboardDismissal {
    return NO;
}

This fixes the issue.