CListCtrl의 헤더 컨트롤 드래그 & 드랍 및 정렬

//헤더 컨트롤 드래그-앤-드롭 가능
DWORD dwExStyle = m_List.GetExtendedStyle();
m_List.SetExtendedStyle(dwExStyle | LVS_EX_HEADERDRAGDROP );

// 헤더 컨트롤을 통한 정렬을 가능하도록 한다.
m_bAscending = FALSE;
m_List.SortItems(&CHeadCtrlDemoDlg::CompareItem, (DWORD_PTR)this);
UpdateArrow();

// 헤더 컨트롤의 HDN_ITEMCLICK 메시지 핸들러
void CHeadCtrlDemoDlg::OnHdnItemclickList1(NMHDR *pNMHDR, LRESULT *pResult)
{
  LPNMHEADER phdr = reinterpret_cast<LPNMHEADER>(pNMHDR);

  if(phdr->iItem == 0)
  {
    m_bAscending = !m_bAscending;
    UpdateArrow();
    m_List.SortItems(&CHeadCtrlDemoDlg::CompareItem, (DWORD_PTR)this);
  }

  *pResult = 0;
}

// 헤더 컨트롤 정렬 비교 콜백 함수
int CALLBACK CHeadCtrlDemoDlg::CompareItem(LPARAM lParam1, LPARAM lParam2, LPARAM lParamSort)
{
  CHeadCtrlDemoDlg* pDlg = (CHeadCtrlDemoDlg*)lParamSort;

  LVFINDINFO lvFind1, lvFind2;
  lvFind1.flags= LVFI_PARAM;
  lvFind1.lParam= lParam1;
  lvFind2.flags= LVFI_PARAM;
  lvFind2.lParam= lParam2;

  int nIndex1 = pDlg->m_List.FindItem(&lvFind1);
  int nIndex2 = pDlg->m_List.FindItem(&lvFind2);

  CString strText1 = pDlg->m_List.GetItemText(nIndex1, 0);
  CString strText2 = pDlg->m_List.GetItemText(nIndex2, 0);

  int nResult = 0;
  if(pDlg->m_bAscending)nResult = strText2.Compare(strText1);
  else nResult = strText1.Compare(strText2);

  return nResult;
}

// 헤더 컨트롤의 Up/Down 화살표 변경 함수
void CHeadCtrlDemoDlg::UpdateArrow(void)
{
  CHeaderCtrl* pHeaderCtrl = m_List.GetHeaderCtrl();
  HDITEM hdItem;
  TCHAR szBuffer[256];
  ::ZeroMemory(&hdItem, sizeof(hdItem));
  ::ZeroMemory(szBuffer, 256);

  hdItem.mask = -1;
  hdItem.pszText = szBuffer;
  hdItem.cchTextMax = 256;
  pHeaderCtrl->GetItem(0, &hdItem);

  hdItem.fmt &= ~(HDF_SORTDOWN | HDF_SORTUP);

  if(m_bAscending)hdItem.fmt |= HDF_SORTDOWN;
  else hdItem.fmt |= HDF_SORTUP;
  pHeaderCtrl->SetItem(0, &hdItem);
}