FtpFindFirstFile调用问题

使用internet transfer 控件连接至一个FTP服务器上，然后调用FtpFindFirstFile
来获得一个文件夹的创建时间，返回的值全部是0，inter句柄是有值的，不知道是怎么回事。
Public Declare Function FileTimeToSystemTime Lib "kernel32" (lpFileTime As FILETIME, lpSystemTime As SYSTEMTIME) As Long
Public Type SYSTEMTIME
  wYear As Integer
  wMonth As Integer
  wDayOfWeek As Integer
  wDay As Integer
  wHour As Integer
  wMinute As Integer
  wSecond As Integer
  wMilliseconds As Integer
End Type

Private Type FILETIME
  dwLowDateTime As Long
  dwHighDateTime As Long
End Type

Private Type WIN32_FIND_DATA
  dwFileAttributes As Long
  ftCreationTime As FILETIME
  ftLastAccessTime As FILETIME
  ftLastWriteTime As FILETIME '*最后一次被修改的时间
  nFileSizeHigh As Long
  nFileSizeLow As Long
  dwReserved0 As Long
  dwReserved1 As Long
  cFileName As String
  cAlternate As String
End Type

Private Declare Function FtpFindFirstFile Lib "wininet.dll" Alias "FtpFindFirstFileA" _
  (ByVal hFtpSession As Long, _
  ByVal lpszSearchFile As String, _
  lpFindFileData As WIN32_FIND_DATA, _
  ByVal dwFlags As Long, _
  ByVal dwContent As Long) As Long
   

Function FTP_test(hFtp As Long) As String
Dim return_v As WIN32_FIND_DATA, return_day As SYSTEMTIME
ftp_v = FtpFindFirstFile(hFtp, "", return_v, 0, 0)
FTP_test = FileTimeToSystemTime(return_v.ftLastWriteTime, return_day)
End Function

up一下，有没有人呀