How to programmatically force the interface to update in iOS?

In iOS, to force an interface update, you can call the setNeedsDisplay() method on the desired UIView. This method marks the view as needing to be redrawn, and the system will call the draw(_:) method in the next update cycle.

If you need to update the layout and size of subviews, use setNeedsLayout(), followed by layoutIfNeeded() for immediate application of changes.

Example:

myView.setNeedsDisplay() // mark for redrawing

// or to update layout
myView.setNeedsLayout()
myView.layoutIfNeeded()

Thus, to programmatically update the interface, call these methods on the relevant views, which prompts the system to redraw or re-layout the interface.