Popup UIViewController
At the parent controller:
let vc = ViewController()
vc.modalPresentationStyle = .overCurrentContext
vc.modalTransitionStyle = .crossDissolve
present(vc, animated: true, completion: nil)
At the pop up controller, use this to enable showing the parent controller in the background:
self.definesPresentationContext = true
Don't forget to set a translucent background to your pop up controller.
-- Reference from: Presenting a popup view controller programmatically - Reddit --
To make your view controller shown as a popup, you should set the following:
popupVC.modalPresentationStyle = .OverCurrentContext
popupVC.modalTransitionStyle = .CrossDissolve
You should also design your view controller's position, size to make it look like a popup.
Here is my popup that i did before.