How to open system menu in Notepad from separate program in C++? - c++

Question

I am trying to make the system menu in Notepad popup as seen here:
It doesn't have to be the Help menu; any menu will do.
This code brings the window to the foreground and logs 0x204a4 0x2bd041f 0 but doesn't open the menu.
#include <iostream>
#include <windows.h>
int main() {
HWND hWnd = FindWindow(NULL, "Untitled - Notepad");
SetForegroundWindow(hWnd);
HMENU hMenu = GetSystemMenu(hWnd, FALSE);
int flag = TrackPopupMenu(hMenu, TPM_LEFTALIGN | TPM_LEFTBUTTON, 452, 335, NULL, hWnd, NULL);
std::cout << hWnd << " " << hMenu << " " << flag << std::endl; // 0x204a4 0x2bd041f 0
SendMessage(hWnd, WM_SYSCOMMAND, flag, 0);
}
g++ main.cpp
UPDATE:
Here is my updated code. It opens the wrong menu:
#ifndef UNICODE
#define UNICODE
#endif
#include <windows.h>
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR pCmdLine, int nCmdShow) {
const wchar_t CLASS_NAME[] = L"My Window Class";
WNDCLASS wc = {};
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.lpszClassName = CLASS_NAME;
RegisterClass(&wc);
HWND hwnd = CreateWindowEx(0, CLASS_NAME, L"My Window", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);
if (hwnd == NULL) {
return 0;
}
ShowWindow(hwnd, nCmdShow);
//--------------------------------------------------------------
HWND hWndNotepad = FindWindow(NULL, L"Untitled - Notepad");
if (!hWndNotepad) {
MessageBox(hwnd, L"Notepad window handle not found.", L"Error", MB_OK | MB_ICONERROR);
}
if (!SetForegroundWindow(hWndNotepad)) {
MessageBox(hwnd, L"Unable to bring Notepad window to front.", L"Error", MB_OK | MB_ICONERROR);
}
HMENU hMenu = GetSystemMenu(hWndNotepad, FALSE);
if (!hMenu) {
MessageBox(hwnd, L"Notepad menu handle not found.", L"Error", MB_OK | MB_ICONERROR);
}
TrackPopupMenuEx(hMenu, TPM_LEFTALIGN | TPM_LEFTBUTTON, 452, 335, hwnd, NULL);
//--------------------------------------------------------------
MSG msg = {};
while (GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return 0;
}
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
switch (uMsg) {
case WM_CREATE:
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
case WM_PAINT: {
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hwnd, &ps);
FillRect(hdc, &ps.rcPaint, (HBRUSH)(COLOR_WINDOW + 1));
EndPaint(hwnd, &ps);
break;
}
return 0;
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

Answer 1

#ifndef UNICODE
#define UNICODE
#endif
#include <windows.h>
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR pCmdLine, int nCmdShow) {
const wchar_t CLASS_NAME[] = L"My Window Class";
WNDCLASS wc = {};
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.lpszClassName = CLASS_NAME;
RegisterClass(&wc);
HWND hwnd = CreateWindowEx(0, CLASS_NAME, L"My Window", WS_OVERLAPPEDWINDOW, 683 - 100, 360 - 150, 300, 200, NULL, NULL, hInstance, NULL);
if (hwnd == NULL) {
return 0;
}
ShowWindow(hwnd, nCmdShow);
//--------------------------------------------------------------
HWND hWndNotepad = FindWindow(NULL, L"Untitled - Notepad");
if (!hWndNotepad) {
MessageBox(hwnd, L"Notepad window handle not found.", L"Error", MB_OK | MB_ICONERROR);
return 0;
}
HMENU hMenu = GetMenu(hWndNotepad);
if (!hMenu) {
MessageBox(hwnd, L"Notepad menu handle not found.", L"Error", MB_OK | MB_ICONERROR);
return 0;
}
tagTPMPARAMS tpm_params;
tpm_params.cbSize = sizeof(tagTPMPARAMS);
GetWindowRect(hWndNotepad, &tpm_params.rcExclude);
TrackPopupMenuEx(GetSubMenu(hMenu, 0), NULL, tpm_params.rcExclude.left, tpm_params.rcExclude.top, hwnd, NULL);
//--------------------------------------------------------------
MSG msg = {};
while (GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return 0;
}
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
switch (uMsg) {
case WM_CREATE:
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
case WM_PAINT: {
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hwnd, &ps);
FillRect(hdc, &ps.rcPaint, (HBRUSH)(COLOR_WINDOW + 1));
EndPaint(hwnd, &ps);
break;
}
return 0;
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}
g++ main.cpp -mwindows