Example code that was made very shortly ago:
Code:
#include <windows.h>
BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
DWORD processId;
GetWindowThreadProcessId(hwnd, &processId);
if(lParam == processId)
PostMessage(hwnd, WM_YOURMESSAGE, 0, 0);
return TRUE;
}
int main(int argc, char *argv[]) {
STARTUPINFO siInfo;
PROCESS_INFORMATION piInfo;
ZeroMemory(&siInfo, sizeof(siInfo));
ZeroMemory(&piInfo, sizeof(piInfo));
CreateProcess
("C:\\WINDOWS\\Notepad.exe", "", 0, 0,
FALSE, CREATE_DEFAULT_ERROR_MODE, 0, 0,
&siInfo, &piInfo);
WaitForSingleObject(piInfo.hProcess, 1000);
EnumWindows(&EnumWindowsProc, piInfo.dwProcessId);
return 0;
}