setneedsdisplay – Tarik Billa

When do I need to call setNeedsDisplay in iOS?

March 2, 2023 by Tarik

You should only be calling setNeedsDisplay if you override drawRect in a subclass of UIView which is basically a custom view drawing something on the screen, like lines, images, or shapes like a rectangle. So you should call setNeedsDisplay when you make changes to few variables on which this drawing depends and for view to … Read more

setNeedsLayout and setNeedsDisplay

February 24, 2023 by Tarik

Actually the documentation is pretty clear about this: setNeedsLayout will layout subviews Call this method on your application’s main thread when you want to adjust the layout of a view’s subviews. setNeedsDisplay will call for a redraw of your view (drawRect:, etc). You can use this method or the setNeedsDisplayInRect: to notify the system that … Read more