Private Sub object_FileTransferData(FileData())

The FileTransferData Event syntax has these parts:

FileTransferData event is fired during file transfers when LocalPath property (and LocalPath argument in GetFile or PutFile methods) isn't set, or is set to "" (empty string). In such cases, GetFile and PutFile methods will not open local file for reading/writing, instead they will fire this event allowing you to read/write data from remote file  from/to byte array.

Since FileData argument is a byte array, file contents can be changed in size and in values - you can supply new byte array to this argument if needed. For example, following code will always destroy all values in the array, and no matter how large files user tries to upload (or download), it will always end up with zero sized file:

Private Sub FtpDLX1_FileTransferData(FileData() As Byte)
  Dim b() As Byte
  DirData = b
End Sub

 

For downloads: In order to determine exactly how many bytes are in FileData array, you should calculate it like this (VB example):

UBound(FileData) - LBound(FileData) + 1

Remember that FileData(0) is the first element in the array.

For uploads: to create new byte array and put some data inside, so it is transferred to remote side, you can use code similar to this (VB example):

Private Sub Ftp1_FileTransferData(FileData() As Byte)
   Dim a As String
   a = "some text"
   ReDim FileData(Len(a) - 1)

   Dim i As Integer
   For i = 0 To Len(a) - 1
      FileData(i) = Asc(Mid$(a, i + 1, 1))
   Next i
Exit Sub