WM_CLOSE doesn't work and the application is not resizable - c++

Question

When I attempt to close the dialog, I expect the application to close, but it doesn't. I assume something is wrong with WM_CLOSE.
The application is not resizable. How do I make it so?
Do I really need UpdateWindow(hWnd)?
#include <Windows.h>
#include "resource.h"
#pragma comment(linker, "\"/manifestdependency:type='win32' \
name='Microsoft.Windows.Common-Controls' version='6.0.0.0' \
processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
#pragma comment(linker, "/SUBSYSTEM:WINDOWS")
INT_PTR CALLBACK DialogProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
switch (Message)
{
case WM_INITDIALOG:
return TRUE;
case WM_CLOSE:
DestroyWindow(hwnd);
PostQuitMessage(0);
return FALSE;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDOK:
EndDialog(hwnd, IDOK);
break;
case IDCANCEL:
EndDialog(hwnd, IDCANCEL);
break;
}
break;
default:
return FALSE;
}
return TRUE;
}
int WINAPI WinMain(
_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPSTR lpCmdLine,
_In_ int nShowCmd
)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
HWND hWnd = CreateDialogParamW(hInstance, MAKEINTRESOURCEW(IDD_MAIN), nullptr, &DialogProc, 0);
if (!hWnd)
{
MessageBoxW(nullptr, L"Dialog Creation Failed!", L"Error!", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hWnd, nShowCmd);
UpdateWindow(hWnd);
MSG msg;
while (GetMessageW(&msg, hWnd, 0, 0))
{
TranslateMessage(&msg);
DispatchMessageW(&msg);
}
return msg.wParam;
}
Resource.rc
// Microsoft Visual C++ generated resource script.
//
#include "resource.h"
#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "winres.h"
/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
// English (United States) resources
#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//
1 TEXTINCLUDE
BEGIN
"resource.h\0"
END
2 TEXTINCLUDE
BEGIN
"#include ""winres.h""\0"
END
3 TEXTINCLUDE
BEGIN
"\r\n"
"\0"
END
#endif // APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// DESIGNINFO
//
#ifdef APSTUDIO_INVOKED
GUIDELINES DESIGNINFO
BEGIN
IDD_MAIN, DIALOG
BEGIN
LEFTMARGIN, 7
RIGHTMARGIN, 302
TOPMARGIN, 7
BOTTOMMARGIN, 169
END
END
#endif // APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//
IDD_MAIN DIALOGEX 0, 0, 309, 176
STYLE DS_SETFONT | DS_MODALFRAME | DS_FIXEDSYS | WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Test"
FONT 8, "MS Shell Dlg", 400, 0, 0x1
BEGIN
LISTBOX IDC_LIST2,48,30,235,56,LBS_SORT | LBS_NOINTEGRALHEIGHT | WS_VSCROLL | WS_TABSTOP
GROUPBOX "Static",IDC_STATIC,146,92,48,40
PUSHBUTTON "Button1",IDC_BUTTON1,215,127,50,14
END
/////////////////////////////////////////////////////////////////////////////
//
// AFX_DIALOG_LAYOUT
//
IDD_MAIN AFX_DIALOG_LAYOUT
BEGIN
0
END
#endif // English (United States) resources
/////////////////////////////////////////////////////////////////////////////
#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//
/////////////////////////////////////////////////////////////////////////////
#endif // not APSTUDIO_INVOKED
resource.h
//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ generated include file.
// Used by Resource.rc
//
#define IDD_MAIN 103
#define IDC_LIST2 1005
#define IDC_BUTTON1 1006
// Next default values for new objects
//
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE 105
#define _APS_NEXT_COMMAND_VALUE 40001
#define _APS_NEXT_CONTROL_VALUE 1007
#define _APS_NEXT_SYMED_VALUE 101
#endif
#endif

Answer 1

The problem is you are passing hWnd as a parameter to GetMessage(). This causes GetMessage() to only retrieve messages for the window. But WM_QUIT is not sent to your window, but to your thread. Since GetMessage() never retrieves the WM_QUIT message, the message loop never exits.
The proper approach is to pass nullptr instead of hWnd.