FIX: SIZE Command Does Not Work in Internet Transfer Control

MORE INFORMATION

The following code illustrates the problem:

Private Sub Command1_Click()
    Inet1.Execute "ftp://server", "size /"
End Sub

Private Sub Inet1_StateChanged(ByVal State As Integer)
    Dim vtData As Variant ' Data variable.
    Select Case State
    ' ... Other cases are not shown.

    Case icResponseCompleted ' 12
        vtData = Inet1.GetChunk(1024)
    End Select

    Text1.Text = vtData
End Sub
				

An example of the code that is necessary to implement the workaround is available in the VBFTP.exe sample, which is available from the following Microsoft Knowledge Base article: This sample uses the FtpFindFirstFile and InternetFindNextFile functions to populate a tree view of the files that are available on the FTP server. A WIN32_FIND_DATA structure is passed to these functions that, after the function is run, will contain the size of the found file. The WIN32_FIND_DATA structure contains the nFileSizeHigh and nFileSizeLow members, which represent the size of the file. The Win32 Software Development Kit (SDK) describes these members as follows: MAXDWORD is defined in WinNT.h as follows:

#define MAXDWORD    0xffffffff
				

This can be defined in Visual Basic as follows:

Public Const MAXDWORD = &Hffffffff
				

IMPORTANT: WinInet uses a LIST command to gather information about the files on an FTP server. Some FTP servers do not return data in a format that WinInet can parse. In this case, the above work around will not work.