CFileDialog的钩子函数解决对话框的多选之DoModal问

   
   // 钩子函数
   UINT_PTR CALLBACK MyOFNHookProc( HWND hdlg, // handle to child dialog box
   UINT uiMsg, // message identifier
   WPARAM wParam, // message parameter
   LPARAM lParam // message parameter
   )
   {
   int nResult = FALSE;
   if (hdlg == NULL)
   return 0;
   #ifdef _DEBUG
   // from "_AfxCommDlgProc()" of the file "dlgcomm.cpp"
   _AFX_THREAD_STATE* pThreadState = AfxGetThreadState();
   if (pThreadState->m_pAlternateWndInit != NULL)
   pThreadState->m_pAlternateWndInit = NULL;
   #endif
   switch(uiMsg)
   {
   case WM_NOTIFY:
   {
   LPOFNOTIFY pOfn = (LPOFNOTIFY)lParam;
   switch(pOfn->hdr.code)
   {
   case CDN_SELCHANGE:
   {
   TCHAR dummy_buffer;
   // Get the required size for the 'files' buffer
   HWND hOwner = GetParent(hdlg);
   HWND hParent = GetParent(hOwner);
   UINT nfiles = CommDlg_OpenSave_GetSpec(hOwner, &dummy_buffer, 1);
   // Get the required size for the 'folder' buffer
   int cbLength = CommDlg_OpenSave_GetSpec(GetParent(hdlg), NULL, 0);
   cbLength += _MAX_PATH;
   if(cbLength>(pOfn->lpOFN)->nMaxFile)
   {
   delete (pOfn->lpOFN)->lpstrFile;
   (pOfn->lpOFN)->lpstrFile = new TCHAR[cbLength];
   ZeroMemory((pOfn->lpOFN)->lpstrFile,cbLength);
   (pOfn->lpOFN)->nMaxFile = cbLength;
   }
   nResult = TRUE;
   break;
   }
   default:
   break;
   }
   break;
   }
   default:
   break;
   }
   return nResult;
   }
   #define NAMEBUF 1024
   // 调用函数
   void CMultiSelectDlg::OnButton1()
   {
   m_listbox.ResetContent();
   m_static.SetWindowText(_T("0 files selected"));
   TCHAR szFilters[]= _T("MyType Files (*.doc)|*.doc||");
   // Create an Open dialog; the default file name extension is ".doc".
   CFileDialog fileDlg(TRUE, _T("doc"), _T("*.doc"),
   OFN_FILEMUSTEXIST | OFN_HIDEREADONLY|OFN_ALLOWMULTISELECT, szFilters);
   fileDlg.m_ofn.lpstrFile=new TCHAR[NAMEBUF]; // 重新定义lpstrFile 缓冲大小
   memset(fileDlg.m_ofn.lpstrFile,0,NAMEBUF); // 初始化定义的缓冲
   fileDlg.m_ofn.nMaxFile = NAMEBUF; // 重定义nMaxFile
   fileDlg.m_ofn.lpfnHook = (LPOFNHOOKPROC)MyOFNHookProc;
   INT_PTR ret = fileDlg.DoModal();
   if (ret == IDOK)
   {
   int width = 0;
   CString str;
   CDC *pDC = m_listbox.GetDC();
   int saved = pDC->SaveDC();
   pDC->SelectObject(GetFont());
   UINT count = 0;
   POSITION pos = fileDlg.GetStartPosition();
   while (pos)
   {
   str = fileDlg.GetNextPathName(pos);
   m_listbox.AddString(str);
   CSize size(0, 0);
   size = pDC->GetTextExtent(str);
   width = width > size.cx ? width : size.cx;
   ++count;
   }
   pDC->RestoreDC(saved);
   ReleaseDC(pDC);
   m_listbox.SetHorizontalExtent(width + 5);
   str.Format(_T("%u files selected"), count);
   m_static.SetWindowText(str);
   }
   DWORD dwCode = CommDlgExtendedError();
   if (FNERR_BUFFERTOOSMALL==dwCode)
   {
   AfxMessageBox(_T("获取文件路径失败！"));
   }
   delete []fileDlg.m_ofn.lpstrFile;
   fileDlg.m_ofn.lpstrFile = NULL;
   }