GetWindowTextLength() = crash ?

hey, i'm having a problem with an MDI text editor where every time i try to call GetWindowTextLength(), my program crashes. EVERY TIME. :( its rather irritating and frustrating and if anyone knows why, the information would be greatly appreciated :) or even if anyone has a shot in the dark..anything.. lol thanks


oh yea, and i'm using the function in order to find out how much text has been entered in my edit control so that i can allot enough space in memory to hold the text in a buffer.

Can you post a small example that demonstrates the issue?

Either the HWND you're passing GetWindowTextLength() is invalid or your process/memory has already been corrupted to the point that GetWindowTextLength() is just a victim and not the cause.

gg

as an update, i can make it tell me that theres no text in the dialog :)

Code:

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case ID_ENC_ENCRYPT:
{
    char algorithm[31] = "Az!By@Cx#Dw$Ev%Fu^Gt&Hs*Ir(Js)";
    TCHAR *buf;
    char *converted_int;
    int i, len;
    HWND hEdit = GetDlgItem(hwnd, IDC_CHILD_EDIT);
                       
    len = GetWindowTextLength(hEdit);
    buf = (TCHAR *)malloc(len+1);
    if (len <= 0) { MessageBox(hwnd, "There is no text to encrypt.", "Error.", MB_OK | MB_ICONERROR); return FALSE; }
    GetDlgItemText(hwnd, IDC_CHILD_EDIT, buf, len);
                       
    for (i = 0; i <= len; i++)
    {
        buf[i] = buf[i] ^ algorithm[i % 30];
    }
                       
    SendMessage(hEdit, WM_SETTEXT, 0, (LPARAM)buf);
                       
    free(buf);
}
break;

---

that codes give me the "a programmer f*d up and Microsoft wants to hear about it :)" message.
*bites tongue*
uhm.......for some reason its working.?.this time...all i did was remove some comments and some MessageBox's that were telling me how far into the function the program got.

mm..it seems i found the problem to be trying to have a messagebox display an int. the var "len" was an int, but i had the code:

Code:

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MessageBox(hwnd, (LPCSTR)len, "Contents of: len", MB_OK | MB_ICONINFORMATION);

---

and that freaked things out. hmm..explanation?

but i'm still getting a "there's no text entered" in a dif function.

Code:

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BOOL CALLBACK SetPassProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
    switch(Message)
    {
        case WM_COMMAND:
            switch(LOWORD(wParam))
            {
                case ID_PASSBTN:
                {
                    int TxtLen;
                    HWND hEdit = GetDlgItem(hwnd, ID_PWDPROMPT);
                       
                    TxtLen = SendMessage(hEdit, WM_GETTEXTLENGTH, 0, 0);
                    TCHAR *buf = (TCHAR *)malloc (TxtLen+1);
                    GetWindowText(hEdit, buf, TxtLen);
                    if (TxtLen <= 0)
                    { MessageBox(hwnd, "There is no text entered.", "Error.", MB_OK | MB_ICONERROR); return FALSE; }
                    GetDlgItemText(hwnd, ID_PWDPROMPT, buf, TxtLen);
                        /* other code that doesn't get executed. */
                }
                break;
            }
        break;
        default:
            return FALSE;
        break;
    }
    return TRUE;
}

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