c++ builder选择文件夹

bcb6自带的opendialog只能打开文件，文件夹不行！

#include   "FileCtrl.hpp"  
  const   SELDIRHELP   =   1000;  
   
   
  AnsiString   Dir   =   "C://";  
      if   (SelectDirectory(Dir,   TSelectDirOpts()   <<   sdAllowCreate   <<   sdPerformCreate   <<   sdPrompt,SELDIRHELP))  
      {  
          int   tt=0;  
      }