这样子来判断目录和文件，能不能办到？？？很复杂！

Dim FilesCount As Long

Dim MaxCount As Long

Private Sub Command1_Click()

   Msgbox "最大的数是：" & GetFolderMaxCount("C:\ttt", 0)   '只查询单层的效果

   Msgbox "最大的数是：" & GetFolderMaxCount("C:\ttt", 2)   '最多深入查询三层目录查询的效果

   Msgbox "最大的数是：" & GetFolderMaxCount("C:\ttt")   '查询指定目录里（包含全部子目录）的效果



End Sub

Public Function GetFolderMaxCount(FolderPath As String, Optional RecursionLayer As Long = -1) As Long

   MaxCount = 0

   GetFolderMaxCount = RecursionFolder(FolderPath, RecursionLayer)

End Function

Private Function RecursionFolder(FolderPath As String, Optional RecursionLayer As Long = -1) As Long

   Dim ReturnString As String, ReadAttrib As Long, TempString As String

   Dim FolderList() As String, FolderListCount As Long, X As Long

   Dim NowNumeric As Long

   If Right(FolderPath, 1) <> "\" Then

      FolderPath = FolderPath & "\"

   End If

   ReturnString = Dir(FolderPath, vbDirectory + vbHidden + vbSystem + vbReadOnly)

   Do

      ReturnString = Dir(, vbHidden + vbSystem + vbReadOnly)

      If ReturnString <> "" Then

         ReadAttrib = GetAttr(FolderPath & ReturnString)

         ReadAttrib = ReadAttrib / (2 ^ 4)

         ReadAttrib = ReadAttrib And 1

         If ReadAttrib = 1 Then

            '属于目录

            If ReturnString <> "." And ReturnString <> ".." Then

               If IsNumeric(ReturnString) = True Then

                  '目录属于数字名称

                  NowNumeric = Int(ReturnString)

                  If MaxCount < NowNumeric Then

                     MaxCount = NowNumeric

                  End If

               End If

               

               On Error GoTo NewArray

               FolderListCount = UBound(FolderList)

               FolderListCount = FolderListCount + 1

               ReDim Preserve FolderList(1 To FolderListCount)

               GoTo SetArrayValue

NewArray:

               FolderListCount = 1

               ReDim FolderList(1 To FolderListCount)

SetArrayValue:

               FolderList(FolderListCount) = FolderPath & ReturnString



            End If

         Else

            '属于文件

            If Len(ReturnString) > 4 Then

               If UCase(Right(ReturnString, 4)) = ".TXT" Then

                  TempString = Left(ReturnString, Len(ReturnString) - 4)

                  If IsNumeric(TempString) = True Then

                     '文件名属于数字名称

                     NowNumeric = Int(TempString)

                     If MaxCount < NowNumeric Then

                        MaxCount = NowNumeric

                     End If

                  End If

               End If

            End If

         End If

      End If

   Loop While ReturnString <> ""

   On Error GoTo NoFolder

   FolderListCount = UBound(FolderList)

   For X = 1 To FolderListCount

      If RecursionLayer <> -1 Then

         If RecursionLayer > 0 Then

            Call RecursionFolder(FolderList(X), RecursionLayer - 1)

         End If

      Else

         Call RecursionFolder(FolderList(X), RecursionLayer)

      End If

   Next X

NoFolder:

   RecursionFolder = MaxCount

End Function