화면 최대화 <-> 원래 화면

/////// 전역변수 ///////

  int _style;
  CRect _originWindow;

////////////////////////


void CEx2Dlg::OnBnClickedButton1() // 전체화면
{
	int windowWidth = GetSystemMetrics(SM_CXSCREEN);
	int windowHeight = GetSystemMetrics(SM_CYSCREEN);
	_style = ::GetWindowLong(this->m_hWnd, GWL_STYLE);
	::GetWindowRect(this->m_hWnd, &_originWindow);
	::SetWindowLong(this->m_hWnd, GWL_STYLE, NULL);
	SetWindowPos(&wndTopMost, 0, 0, windowWidth, windowHeight, NULL);
	ShowWindow( SW_MAXIMIZE );
}



void CEx2Dlg::OnBnClickedButton2() // 원래대로
{
	::SetWindowLong(this->m_hWnd, GWL_STYLE, _style);
	SetWindowPos(GetParent(), _originWindow.left, _originWindow.top, 
	_originWindow.right - _originWindow.left, _originWindow.bottom - _originWindow.top, NULL);
}