🚀 go-pugleaf

ezeller@iiic.ethz.ch (Emil Johann Zeller) writes:

>MRESULT ClientWinProc(HWND hwnd, USHORT msg, MPARAM mp1,
>           MPARAM mp2)
>{
>  HWND hwndControl;
   ^^^^^^^^^^^^^^^^

This is your problem. You are aware of the fact that EVERY time your window
proceedure gets a message, these variables are created and then deleted
when the procedure exits?  This is a LOCAL variable.  You need global storage.

>    case CWPM_CREATE:
>      hwndControl = WinCreateWindow(hwnd, WC_BUTTON, "Beep on WM_PAINT",
>                            WS_VISIBLE | BS_AUTOCHECKBOX,
>                            cx - 100, cy - 10, 200, 20, hwnd,
>                            HWND_TOP, ID_BUTTON, NULL, NULL);
>    case WM_PAINT:
>      if (SHORT1FROMMR(WinSendMsg(hwndControl, BM_QUERYCHECK, NULL, NULL))) WinAlarm(HWND_DESKTOP, WA_NOTE);
>      return(WinDefWindowProc(hwnd, msg, mp1, mp2));
>      break;

When this statement is executed, hwndControl is undefined. Either define your
variable outside the context of the window procedure, or use the window word
to store the handle.

Here's another suggestion that is better than the other two. If you change
your WM_PAINT processing to: 

if (SHORT1FROMMR(WinSendMsg( WinWindowFromID(hwnd, ID_BUTTON),
                             BM_QUERYCHECK,
                             NULL,
                             NULL)
                 )
   )
   WinAlarm(HWND_DESKTOP, WA_NOTE);

you won't need the variable. WinWindowFromID returns the window handle of
a window given the window's parent and the unique window id. This will only
work if all children of hwnd have unique id's. (or at least the window id
you are querying is unique.)


______________________________________________________________________________
     Michael Harris - harris@catt.ncsu.edu or harris@carvm3.vnet.ibm.com
 System Administrator, Computer & Technologies Theme Program, NC State Univ.
(My opinions are my own and do not represent those of NCSU or IBM Corporation)