Exception:noStream(com/visual-prolog/stream/stream_exception)The predicate has no stream assigned
Predicate name = stdio::readLine
I want in the onShow( ) clause of a window to read an integer from the keyboard if possible and show it with stdio::write(N). I can dsiplay data with stdio::write(N) in the windows drawing area no problem. It must not be in the onShow( ) clause I can add a menu item and call some code instead.
A GUI program does not have an input stream. A GUI program uses menu, dialogs, forms, editors and the like to interact with the user. See the tutorial Fundamental Visual Prolog - GUI.