Shell extension to make executables as services

#include "WndHelpers.h"

void 
CenterWindow(HWND hWnd)
{
	int cx, cy, dx, dy;
	HDC hDC;
	HWND hDeskWnd;
	RECT rc;

	GetWindowRect(hWnd, &rc);

	hDeskWnd = GetDesktopWindow();
	hDC = GetDC(hDeskWnd);
	cx = GetDeviceCaps(hDC, HORZRES);
	cy = GetDeviceCaps(hDC, VERTRES);
	DeleteDC(hDC);

	dx = rc.right - rc.left;
	dy = rc.bottom - rc.top;
	cx = (cx - dx) / 2;
	cy = (cy - dy) / 2;

	MoveWindow(hWnd, cx, cy, dx, dy, TRUE);
}

void __stdcall
MultipleCBAddStringByDlgId(HWND hwndDlg, int nCtlId, int nStringCount, ...)
{
	register int x;
	va_list marker;

	if(!IsWindow(hwndDlg))
		return;

	va_start(marker, nStringCount);
	for(x = 0; x < nStringCount; x++)
	{
		SendMessage(GetDlgItem(hwndDlg, nCtlId), CB_ADDSTRING, 0, (LPARAM)(LPCTSTR)va_arg(marker, LPCTSTR));
	}
	va_end(marker);
}

void
MultipleShowWindowByDlgId(HWND hwndDlg, BOOL fShow, int nCtlIdCount, ...)
{
	register int x;
	va_list marker;

	if(!IsWindow(hwndDlg))
		return;

	va_start(marker, nCtlIdCount);
	for(x = 0; x < nCtlIdCount; x++)
	{
		ShowWindow(GetDlgItem(hwndDlg, (UINT)va_arg(marker, UINT)), fShow ? SW_SHOW : SW_HIDE);
	}
	va_end(marker);
}