Win32 application exits immediately after closing the dialog box

[EDITED adds: It turns out that the answer is very boring and has nothing to do with Win32, dialogs, etc. I just had an idiotic bug in my code. Thanks to Hans Passant for noticing.]

(This is quite a long time. Short description: I have a simple Win32 application that creates an icon in the notification area, never shows its main window and has a "about" field that can be displayed by right-clicking on the notification area icon. For no reason I can understand when the "about" window is displayed and then closed, the main application message loop receives an exit message and ends. What could I do wrong to cause this?)

I am writing a small program, which is located in the notification area ("system tray"), and runs various processing bits that are inappropriate here in the background. Its user interface is almost trivial: you can right-click the area icon to get a menu, with the options "Exit" and "About"; the first leaves, the last pops up a little about the modal dialog box of this program.

The application is written in C ++ and uses Win32 directly (without MFC or anything else). I apologize for being stuck in the Stone Age.

The only problem is this: when the "About" dialog is closed, the program ends! What could be the reason for this?

, . .

• Windows "" , .
  • proc WM_CTLCOLORBTN
  • () WM_ENABLE (TRUE).
  • WM_CTLCOLORBTN, WM_IMESETCONTEXT, WM_SETFOCUS, WM_WINDOWPOSCHANGING, WM_WINDOWPOSCHANGED, 3xWM_GETICON, WM_NCACTIVATE, 2xWM_GETICON, WM_ACTIVATE, WM_WINDOWPOSCHANGING.
  • ges WM_WINDOWPOSCHANGING, WM_NCACTIVATE, 0x93, 0x93, 0x91, 0x92, 0x92 ( ?), WM_ACTIVATE.
  • WM_KILLFOCUS, WM_IME_SETCONTEXT.
  • WM_IME_SETCONTEXT.
  • WM_IME_NOTIFY; .
  • WM_SETFOCUS.
  • 0x90, WM_DESTROY, WM_NCDESTROY.
• proc, .
• GetMessage 0 ( WM_QUIT) .
• PostQuitMessage WndProc, , WM_DESTROY, .

, - , - . ( , , ).

WinMain :

WNDCLASSEX wc;
// fill in fields of wc
RegisterClassEx(&wc);

HWND w = CreateWindow(...);

NOTIFYICONDATA nid;
memset(&nid, 0, sizeof(nid));
// fill in fields of nid
Shell_NotifyIcon(NIM_ADD, &nid);

// (start a background thread to do the real work,
// which is of no interest here)

MSG msg;
while (GetMessage(&msg, NULL, 0, 0)) {
  if (TranslateAccelerator(msg,hwnd, accel, &msg)) continue;
  TranslateMesage(&msg);
  DispatchMessage(&msg);
}

Shell_NotifyIcon(NUM_DELETE, &nid);
return (int)msg.wParam;

WndProc :

switch (message) {
  case WM_USER_SHELLICON: // my own, attached to the icon menu
    if (LOWORD(lParam) == WM_RBUTTONDOWN) // ... create menu and return TRUE
    break;
  case WM_COMMAND:
    // menu item
    switch (LOWORD(wParam)) {
      case IDM_ABOUT:
        DialogBox(the_instance, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, AboutProc);
        break;
      case IDM_EXIT:
        DestroyWindow(hWnd);
        break;
      default: return DefWindowProc(hWnd, message, wParam, lParam);
    }
  case WM_DESTROY:
    PostQuitMessage(0);
    break;
  default: return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;

proc :

switch (message) {
  case WM_INITDIALOG:
    // fill in a version string
    return (INT_PTR)TRUE;
  case WM_COMMAND:
    if (LOWORD(wParam)==IDOK || LOWORD(wParam)==IDCANCEL) {
      EndDialog(hDlg, LOWORD(wParam));
      return (INT_PTR)TRUE;
    }
    break;
}
return (INT_PTR)FALSE;