?
Solved

Stubborn Combo Box appears to ignore my LB_ADDSTRING messages.

Posted on 1997-01-07
1
Medium Priority
?
393 Views
Last Modified: 2013-12-03
I have been attempting to insert five strings into a combo box, to no avail.  Not only do the strings not display, but my DBWin app reports "err DLG_LBOX 02AF:B39F: Invalid string pointer: 0000:0000".  Here is the dialog procedure I'm using:

/* Start of C Code */
BOOL FAR PASCAL MainDlgProc(HWND hDlg, UINT msg, WPARAM wP, LPARAM lP)
{
    switch (msg)
    {
        case WM_INITDIALOG:
        {
            HWND hwLBox;
            DWORD dwRet;
            int i;

            LPSTR prgNames[5]={"File Manager", "Character Map", "Windows Help", "Solitaire", "Minesweeper"};

            hwLBox=GetDlgItem(hDlg, IDL_PROGS);
            if(hwLBox==NULL)
                MessageBox(NULL, "Debugging message number 0 inserted in \"DLG_LBOX.C\" on 05-Jan-1997 at 12:18:05", "Debugging Message...", MB_APPLMODAL|MB_ICONINFORMATION|MB_OK);
            dwRet=SendMessage(hwLBox, LB_RESETCONTENT, 0, 0L);
            if(dwRet==LB_ERR)
                MessageBox(NULL, "Debugging message number 1 inserted in \"DLG_LBOX.C\" on 04-Jan-1997 at 11:54:57", "Debugging Message...", MB_APPLMODAL|MB_ICONINFORMATION|MB_OK);
            for(i=0;i==4;i++)
                SendMessage(hwLBox, LB_ADDSTRING, 0, (LPARAM)(LPSTR)prgNames[i]);
            return FALSE;
            }
            break;

        case WM_COMMAND:
            switch(wP)
            {
                case IDB_EXECUTE:
                {
                    HWND hwLBox;
                    DWORD dwIndex;

                    hwLBox=GetDlgItem(hDlg, IDL_PROGS);
                    dwIndex=SendMessage(hwLBox, LB_GETCURSEL, 0, 0);

                    if(dwIndex==0)
                        WinExec("WINFILE.EXE", 1);
                    if(dwIndex==1)
                        WinExec("CHARMAP.EXE", 1);
                    if(dwIndex==2)
                        WinExec("WINHELP.EXE", 1);
                    if(dwIndex==3)
                        WinExec("SOL.EXE", 1);
                    if(dwIndex==4)
                        WinExec("WINMINE.EXE", 1);
                    if(dwIndex!=LB_ERR)
                        DestroyWindow(hDlg);
                    else
                    {
                        MessageBeep(MB_ICONHAND);
                        MessageBox(hDlg, "Please select a program from the listbox before selecting execute.\0", "Please make a selection...\0", MB_APPLMODAL|MB_ICONHAND|MB_OK);
                    }
                }
                break;
            }
        break;

        case WM_DESTROY:
        {
            HWND hwLBox, hwUnused;

            hwLBox=GetDlgItem(hDlg, IDL_PROGS);
            SendMessage(hwLBox, LB_RESETCONTENT, 0, 0L);
            PostQuitMessage(0);
        }
        break;

        default:
            return FALSE;
            break;
    }
    return TRUE;
}

/* End Code */

So, things appear to be okay.  I've tried just about everything I can think of, including sending each string as a literal using two casts (LPARAM and LPSTR) to send it.  I am going crazy!  If you can give me any help it would be appreciated.  Thank you.

                 Steven Spain
                 SJSME@IX.NETCOM.COM
0
Comment
Question by:sjsme
1 Comment
 

Accepted Solution

by:
msaraiva earned 240 total points
ID: 1298601
Have you tried, instead of SendMessage, PostMessage ?

/* ... */
for(i=0;i==4;i++)
  PostMessage( hwLBox, LB_ADDSTRING, 0, (LPARAM)(LPSTR)prgNames[i]);
/* ... */
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

For a while now I'v been searching for a circular progress control, much like the one you get when first starting your Silverlight application. I found a couple that were written in WPF and there were a few written in Silverlight, but all appeared o…
Entering time in Microsoft Access can be difficult. An input mask often bothers users more than helping them and won't catch all typing errors. This article shows how to create a textbox for 24-hour time input with full validation politely catching …
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
Is your OST file inaccessible, Need to transfer OST file from one computer to another? Want to convert OST file to PST? If the answer to any of the above question is yes, then look no further. With the help of Stellar OST to PST Converter, you can e…

569 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question