Consultor Eletrônico

Status: Unverified

GOAL:

How to use the Win32 API function called SendMessage to retrieve the index number of the selected item in a Selection-List.

FACT(s) (Environment):

Windows 32 Intel
Windows NT 32 Intel/Windows 2000

FIX:

This code assumes a Selection-List named SELECT-1.

&GLOBAL-DEFINE LB_GETCURSEL 392

DEFINE VARIABLE iRC    AS INTEGER NO-UNDO.
DEFINE VARIABLE iEntry AS INTEGER NO-UNDO.

PROCEDURE SendMessageA EXTERNAL "USER32.DLL":
   DEFINE INPUT  PARAMETER hwnd    AS LONG NO-UNDO.
   DEFINE INPUT  PARAMETER wmsg    AS LONG NO-UNDO.
   DEFINE INPUT  PARAMETER wparam  AS LONG NO-UNDO.
   DEFINE INPUT  PARAMETER lparam  AS LONG NO-UNDO.
   DEFINE RETURN PARAMETER rc      AS LONG NO-UNDO.
END PROCEDURE.

/*
  The following RUN statement will retrieve the zero (0) based number
  of the selected item in the list (for single select lists) or the
  first selected item in the list (for multi-select lists)
*/

RUN SendMessageA (INPUT  SELECT-1:HWND,
                 INPUT  {&LB_GETCURSEL},
                 INPUT  0,
                 INPUT  0,
                 OUTPUT iRC).

IF iRC = -1 THEN
   MESSAGE "There Was No Selected Item In The List" VIEW-AS ALERT-BOX.
ELSE
   ASSIGN iEntry = iRC + 1.   /* Add 1 to conform to Progress'
                                 one (1) based indexing */