Running my program it runs and due to me having a menu with EXIT to Destroy the window it runs and immediately exits the window. Unsure how to fix my issue here on compiling the program to have it not run the WindowProcedure function and passing the argument EXITMENU resulting in the Window being destroyed.
*.CPP
#include <windows.h>
#define HELPMENU 1
#define HIGHSCROREMENU 2
#define EXITMENU 3
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR args, int ncmdshow) {
WNDCLASS wc = { 0 }; // WNDCLASSW is a structure
LPCWSTR title = L"Window"; // Long Pointer Constant Wide (UTF-16) String
wc.hbrBackground = (HBRUSH)COLOR_WINDOW; // Background
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_HAND); // Sets Cursor
wc.hInstance = hInst; // Instance of window
wc.lpszClassName = L"windowClass"; // Class name
wc.lpfnWndProc = WindowProcedure; // Pointer to the function // Controller of window handle
if (!RegisterClassW(&wc)) { // Registers the window class
return -1;
}
// | binary combination value, posX, posY, Width, Height
// Creates the window
CreateWindow(wc.lpszClassName, title, WS_OVERLAPPEDWINDOW | WS_VISIBLE | WS_BORDER, 100, 100, 800, 600, NULL, NULL, NULL, NULL);
MSG msg = { 0 };
while (GetMessage(&msg, NULL, NULL, NULL) > 0) { // Keeps the window running
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return 0;
}
/* Event Paths */
LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
switch (msg) {
case WM_CREATE: // On window creation
AddControls(hWnd);
AddMenu(hWnd);
break;
case WM_LBUTTONDOWN: // Left Mouse button
break;
case WM_DESTROY: // Makes GetMessage Function return false, closing the window
PostQuitMessage(0);
return 0;
case EXITMENU:
DestroyWindow(hWnd); // This part of the code shouldn't run on creation
break;
default:
return DefWindowProc(hWnd, msg, wp, lp);
}
}
/* Creates menu */
void AddMenu(HWND hWnd) {
hMenu = CreateMenu(); // Creates menu object
// AppendMenu(Menu Instance, Usage Type, Argument, String info);
AppendMenu(hMenu, MF_STRING, HELPMENU, L"Help - F1");
AppendMenu(hMenu, MF_STRING, HIGHSCROREMENU, L"Highscores - F2"); // Menu Created
AppendMenu(hMenu, MF_STRING, EXITMENU, L"Exit - ESC");
// SetMenu(Window Handle , Menu Instance);
SetMenu(hWnd, hMenu); // Sets menu for window //
}
You are not handling the menu commands correctly in your WindowProcedure()
.
You have defined EXITMENU
as 3, which is the same value as the WM_MOVE
message. So, in your switch
, you are destroying your window as soon as it receives a WM_MOVE
message during window creation.
You need to instead handle the menu commands via the WM_COMMAND
message, per the documentation:
About Menus: Messages Used With Menus
When the user chooses a command item from a menu, the system sends a
WM_COMMAND
message to the window procedure. The low-order word of theWM_COMMAND
message'swParam
parameter contains the identifier of the chosen item. The window procedure should examine the identifier and process the message accordingly.
Try this instead:
LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
switch (msg) {
...
case WM_COMMAND:
switch (wp) {
case HELPMENU: {
...
return 0;
}
case HIGHSCROREMENU: {
...
return 0;
}
case EXITMENU: {
DestroyWindow(hWnd);
return 0;
}
}
break;
}
...
}
return DefWindowProc(hWnd, msg, wp, lp);
}
UPDATE: That being said, consider having your EXITMENU
handler use SendMessage(WM_CLOSE)
instead of DestroyWindow()
. If your app maintains data that should be saved when the app is closed by the user, you can add a WM_CLOSE
handler to perform that action regardless of how the window is being closed (your exit menu, X
close button, Alt-F4, etc). DefWindowProc()
destroys a window when processing WM_CLOSE
.
LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
switch (msg) {
...
case WM_CLOSE: {
if (data has been modified) {
prompt user to save data...
if (cancelled) {
return 0;
}
if (should save) {
save data ...
}
}
break;
}
case WM_COMMAND:
switch (wp) {
...
case EXITMENU: {
SendMessage(hWnd, WM_CLOSE, 0, 0);
return 0;
}
}
break;
}
...
}
return DefWindowProc(hWnd, msg, wp, lp);
}