How do I check if an UIViewController is currently being displayed?

Question

How do I check if an UIViewController is currently being displayed?

My UIViewControllers are listening for NSNotifications - e

Answer 1

It's too late to replay on this question.

To check the instance of a UIViewController is currently on the top of the screen or to check if it is showing on screen, you can put a check like:

// Get the topmost view showing on the screen as below
    UIViewController * currentVC = ((UINavigationController*)app.window.rootViewController).visibleViewController;

// Now check whether the viewcontroller you want to show is the same as the currently showing view controller.
    if (currentVC.class == myVC.class) {  // Here myVC is any/new instance of the viewcontroller you would like to check or show (if not shown).
         // If both are same then it returns true and executes this block of code.
    }