In order to programmatically access controls on a Dialog Builder resource you must first attach an Origin C object of the appropriate type to the control on the dialog. Origin C supports many control types including buttons, check boxes, radio buttons, sliders, edit boxes, combo boxes, list boxes, rich edit boxes, and worksheet and graph controls. The available control types are built-in Origin C classes containing methods and properties. The class methods and properties of each type can be used to manipulate controls on a dialog once an Origin C object of the appropriate type is declared and attached to a control on the dialog. The type of the Origin C object must match the type of the control on the dialog.
The control types (classes) and their methods and properties are prototyped in several Origin C header files in the \OriginC\System subfolder of Origin. These header files also contain reference information for each class and for the class methods and properties. Origin C system header files containing Dialog Builder related classes include Dialog.h, Control.h, mswin.h, and MsgMap.h. The system header file Dialog.h includes all other Dialog Builder related header files. It is sufficient and recommended to include just Dialog.h in any source file used to control Dialog Builder dialogs.
Note: A more organized and readily available but sometimes less complete source of information on the types of Dialog Builder resources accessible from Origin C is the User Interface Controls section in the Classes book of the Origin C Language Reference. The Origin C Language Reference includes reference information for all methods of all Dialog Builder related classes but does not contain information on any class properties (which are few). When looking for Dialog Builder reference information the most efficient method is to look first in the Origin C Language Reference and then, if not found, look in a System header file (most likely Dialog.h or Control.h).