How do I overlay a modalViewController on top of another view without the original disappearing?

Question

I want to show a customised alert panel over my app, but have the previous UIViewController visible in the background. I was hoping to show this as a modal view controller. How do I do this without the previous UIViewController turning black and disappearing?

Answer 1

Instead of showing the new vc as a modal vc, you need to add it as child view controller:

AlertPanelVC *alertVC = ...
[self addChildViewController: alertVC];
alertVC.view.frame = ...; //or something equivalent if you're using auto layout 
[self.view addSubview: alertVC.view];
[alertVC didMoveToParentViewController: self];

To dismiss it:

[alertVC willMoveToParentViewController:nil];
[alertVC.view removeFromSuperview];
[alertVC removeFromParentViewController];