I currently have a UIAlertController being displayed on the screen. The view of the alert should only display 2 elements, a title and a UIActivityIndicato
In swift:
activityIndicator.center = self.view.center
If you have a tool bar or a navController you might want to shift the point but otherwise, center is center...
If you still have issues, perhaps this tutorial would help. If you are trying to center it in a table view controller, this answer might help.