AlertController is not in the window hierarchy

Question

I\'ve just created a Single View Application project with ViewController class. I would like to show a UIAlertController from a function which is located inside my own class

Answer 1

This worked for me:

- (UIViewController *)topViewController{
  return [self topViewController:[UIApplication sharedApplication].keyWindow.rootViewController];
}

- (UIViewController *)topViewController:(UIViewController *)rootViewController
{
  if (rootViewController.presentedViewController == nil) {
    return rootViewController;
  }

  if ([rootViewController.presentedViewController isMemberOfClass:[UINavigationController class]]) {
    UINavigationController *navigationController = (UINavigationController *)rootViewController.presentedViewController;
    UIViewController *lastViewController = [[navigationController viewControllers] lastObject];
    return [self topViewController:lastViewController];
  }

  UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController;
  return [self topViewController:presentedViewController];
}

Implementation:

UIViewController * topViewController = [self topViewController];

Using with alert:

[topViewController presentViewController:yourAlert animated:YES completion:nil];

You can send an alert from any class in your app (that uses UIKit: #import )

Source here.