private void Page_Load(object sender, System.EventArgs e)
  {    
   string strDirlist=@"目录绝对路径";
   DirectoryInfo thisOne=new DirectoryInfo(strDirlist);
   Response.Write("<pre>");
   ListTreeShow(thisOne,0);
   Response.Write("</pre>");
  }

  private void ListTreeShow(DirectoryInfo theDir,int nLevel)//递归目录 文件
  {
   DirectoryInfo[] subDirectories=theDir.GetDirectories();//获得目录
   //for(int i=0;i<subDirectories.Length;i++)
   foreach   (DirectoryInfo   dirinfo   in   subDirectories)
   {
    Response.Write("深度="+nLevel+"<br>");
    Response.Write("文件夹:"+dirinfo.Name+"/r/n<br>");
    FileInfo[]   fileInfo   =dirinfo.GetFiles();   //目录下的文件
    //FileInfo[] fileInfo=dirinfo.GetFiles("*.dwt");//获取指定类型的文件  
    foreach   (FileInfo   fInfo   in   fileInfo)    
    {              
     Response.Write("文件="+fInfo.Name.ToString()+"/r/n/n");   
    }    
    ListTreeShow(dirinfo,nLevel+1);
   }
  }