ios - Whose view is not in the window hierarchy issue?

Question

Warning: Attempt to present on whose view is not in the window hierarchy!

Yes I have looked at the other questions and answers before posting this question. They have not helped me resolve this. Here's what I am doing. I am calling on my singleton class socialHelper to display an action sheet, where postToFacebook method is an option to select. When clicking on this action, I get the Warning above and the postToFacebook is not displayed. I'm calling this from a UIViewController with the UINavigationController as the main controller, and my SocialHelper class is a NSOject.

- (void)postToFacebook
{
    if ([SLComposeViewController isAvailableForServiceType:SLServiceTypeFacebook]) {

    slComposeViewController = [SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];
    [slComposeViewController setInitialText:@"Building stairs? Checkout StairsPro on the app store!"];
    [slComposeViewController addImage:[UIImage imageNamed:@"StairsIcon120x120.png"]];
    [slComposeViewController addURL:[NSURL URLWithString:@"https://itunes.apple.com/us/app/stairs-pro/id477032819?ls=1&mt=8"]];

    [self presentViewController:slComposeViewController animated:YES completion:nil];

    // I've also tried this, which shows the post window, but after hitting cancel or post, my previous viewController is not the current viewController. So my navigation bar is gone and can't move around in my app. 
    // [[[[UIApplication sharedApplication]delegate]window]setRootViewController:slComposeViewController];

    }else{
        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"No Facebook Account" message:@"No Facebook account has been configured. You can configure or create a Facebook account in settings." delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
        [alert show];
}
}

So what I'm asking is what is the best way to get the slComposerViewController to display in this case, also how we could use the UIApplication option as well. Thank you!

Answer 1

I would change the method to pass in the ViewController to make sure the correct VC is presenting it like so:

- (void)postToFacebookFromVC:(UIViewController*) presentingVC

And inside that method when calling presentViewController use:

[presentingVC presentViewController:slComposeViewController animated:YES completion:nil];

I assume then that using your socialHelper singleton class would be something like:

[[socialHelper sharedResource] postToFacebookFromVC:self]; //inside the VC that you want to display it

For your second question on using the rootViewController try this:

[[[[[UIApplication sharedApplication] delegate] window] rootViewController] presentViewController:slComposeViewController animated:YES completion:nil];

Edit: Since the first two suggestions didn't work for your project, try getting the topMost ViewController and presenting slComposeViewController from it instead of "self" like so:

UIViewController *topController = [UIApplication sharedApplication].keyWindow.rootViewController;

while (topController.presentedViewController) {
    topController = topController.presentedViewController;
}

[topController presentViewController:slComposeViewController animated:YES completion:nil];