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
I had the same problem and using frame positioning didn't work for me. Yimin Lin's answer was very close for me, but I just wanted to present an alternative using constraints in non-visual format:
//...
indicator.setTranslatesAutoresizingMaskIntoConstraints(false)
alert.view.addSubview(indicator)
alert.view.addConstraint(NSLayoutConstraint(item: indicator, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: alert.view, attribute: attribute: NSLayoutAttribute.CenterX, multiplier: 1, constant: 0))
alert.view.addConstraint(NSLayoutConstraint(item: indicator, attribute: NSLayoutAttribute.CenterY, relatedBy: NSLayoutRelation.Equal, toItem: alert.view, attribute: attribute: NSLayoutAttribute.CenterY, multiplier: 1, constant: 0))
//...