This example uses WinBeginPaint to obtain and associate a presentation space with the update region of a window so that redrawing can take place.

#define INCL_WINWINDOWMGR       /* Window Manager Functions     */
#include <os2.h>

HWND    hwnd;           /* parent window                        */
RECTL  rcl;             /* update region                        */
HPS    hps;             /* presentation-space handle            */

 case WM_PAINT:
     hps = WinBeginPaint(hwnd,   /* handle of the window      */
         NULLHANDLE,             /* get a cache presentation space */
         &rcl);                  /* receives update rectangle  */
     WinFillRect(hps, &rcl, CLR_WHITE);
     WinEndPaint(hps);