Question

I have an app which has split view inside a tab bar, and these split views often have navigation hierarchy and then sometimes modal views are presents on top of them, and it all works fine, but…

I am trying to display a passcode lock whenever the app goes into background, so I put

[self.window.rootViewController presentModalViewController:lockView animated:YES];

in my AppDelegate’s method

- (void)applicationWillResignActive:(UIApplication *)application

…which works fine unless a modal view is displayed.
the passcode does not display if a modal view is open.

Is there a way to retrieve the currently active view controller so I can present this lock view?

Thanks in advance

Cheerio

---

Code that worked was as follows:

BOOL hasKids = YES;
UIViewController *topViewController = (UIViewController*)[[(UITabBarController*)self.window.rootViewController viewControllers] objectAtIndex:((UITabBarController*)self.window.rootViewController).selectedIndex];

while (hasKids) {
    if (topViewController.presentedViewController) {
        hasKids = YES;
        topViewController = topViewController.presentedViewController;
    } else {
        hasKids = NO;
    }
}

[topViewController presentModalViewController:lockView animated:YES];`

Answer 1

I think the easiest way is to keep track of which tab is currently active (there are a number of ways to do this, but I’d recommend implementing the UITabBarControllerDelegate and handling its tabBarController:didSelectViewController: method).

Once that’s done, you’ll probably need to manage a property in each view controller that holds any modal view controllers you present. If, however, you’re on iOS 5 or higher, look into the UIViewController property presentedViewController. It appears that this is a new way to do exactly what you want.