How to show one viewcontroller over other as overlay in iOS?

Question

I have two view controller which Controller A and B . A controller displaying some info on screen. On top right of A screen I have a UIButton on click of button I want to show a help screen which will have some labels & when I touch the help screen it should go away.

I can do it by adding a view on top of all view & hide, show it. But I want to know how can I show HelpScreenViewController as a semitransparent view controller on top of first view controller on click of UIButton . When I tap on HelpScreenViewController it should go away.

EDIT: I have added below code but does not work

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"TopOverVc"];
    vc.view.backgroundColor = [UIColor clearColor];
    self.modalPresentationStyle = UIModalPresentationCurrentContext;
    [self presentViewController:vc animated:NO completion:nil];

Thanks in advance.

Answer 1

For what you described, you dont need a ViewController to contain the 'TopOver' view. A normal UIView would be better. Place that within your first ViewController, in interface builder. Drag it into your A ViewController class, along with the button. When the button is clicked, just show/hide your view containing the info you need.

Answer 2

You can use the containerView control and you can add the childViewController for it. You can use this as overlay by doing the background colors transparent as your needs.

This article may help help you http://spin.atomicobject.com/2015/07/21/ios-container-views/

One more thing, you can set this containerview hide/visible as you need.