dialog box problem keeps haunting me

hey all,
I am just experimenting as I seem to be having very bad luck with creating dialog boxes with the API.

well, I FINALLY got some code to work that actually displays the dialog box (usually the code will compile fine, but when I execute it there is no sign of the dialog box). :o

here it is:

Code:

---

#include <windows.h>
#include "resource.h"

BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
        switch(uMsg) {
        case WM_INITDIALOG:
                SetDlgItemText(hwndDlg, IDC_EDIT, "hello there");
                return TRUE;
        case WM_CLOSE:
                EndDialog(hwndDlg, 0);
                return TRUE;
        }
        return FALSE;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
        return DialogBox(hInstance, MAKEINTRESOURCE(IDD_DIALOG), NULL, (DLGPROC)DialogProc);
}

---

yes, indeed very simple code. IDC_EDIT is an edit box control on the dialog (obviously). as I said, I figured I'd go real simple with this one since I was having so many troubles with other controls. I was so happy to see that the dialog actually appeared for once.

now here goes my question. on the dialog, there is also an OK (IDOK) button and a Cancel (IDCANCEL) button (by default). now, watch how I handle these button messages:

Code:

---

BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
        switch(uMsg) {
        case WM_INITDIALOG:
                SetDlgItemText(hwndDlg, IDC_EDIT, "hello there");
                return TRUE;
        case WM_COMMAND:
                switch(LOWORD(wParam)) {
                case IDOK:
                        EndDialog(hwndDlg, 0);
                        return TRUE;
                case IDCANCEL:
                        EndDialog(hwndDlg, 0);
                        return TRUE;
                }
        case WM_CLOSE:
                EndDialog(hwndDlg, 0);
                return TRUE;
        }
        return FALSE;
}

---

looks ok, right? thats what I thought. turns out that when I run this after this very small modification I get another one of those non appearing dialog boxes. lol

could anyone here please tell me what looks wrong with the way I am handling those button messages? I would really like to know what I am doing wrong to keep getting these non appearing dialog boxes (like what can cause behaviour like this? I am sure I'm not the only one here that has had this problem). the program appears to be completing execution, so maybe I am adding a return statement somewhere where I shouldn't be?

any help would be greatly appreciated, this same problem has been bugging me for a while now.


thanks in advance! :D

What would happen in your code if a WM_COMMAND message came that was neither IDOK nor IDCANCEL?

There's no default condition in your switch(LOWORD(wParam)) statement, nor is there a return or break after that switch, so any WM_COMMAND apart from IDOK or IDCANCEL will reach the end of that inner switch statement and then keep executing the contents of case WM_CLOSE.

aha. my problem is not writing a break after WM_COMMAND (execution was falling through to WM_CLOSE). I was not expecting any messages to come other than the ones made by my controls. thanks for pointing that out Cat, here is my dialog callback now:

Code:

---

BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
        switch(uMsg) {
        case WM_INITDIALOG:
                SetDlgItemText(hwndDlg, IDC_EDIT, "hello there");
                return TRUE;
        case WM_COMMAND:
                switch(LOWORD(wParam)) {
                case IDOK:
                        EndDialog(hwndDlg, 0);
                        return TRUE;
                case IDCANCEL:
                        EndDialog(hwndDlg, 0);
                        return TRUE;
                default:
                        return DefWindowProc(hwndDlg, uMsg, wParam, lParam);
                }
                break;
        case WM_CLOSE:
                EndDialog(hwndDlg, 0);
                return TRUE;
        }
        return FALSE;
}

---

:)