vb通过FTP下载exe,rar等文件的问题

请先下载这个
http://www.mndsoft.com/blog/article.asp?id=1117

问题：
如何可以在改成二进制下载后，进度条同样有作用？
现在是下载txt文件没有问题，但是exe\rar\zip就不行，如何可以实现ftp下载exe\rar\zip同样可以显示真实的进度条？
有朋友说是这段代码的问题
Public Function GetFiles(strFile As String, strNewFile As String, lngFileSize As Long, vMode As Integer) As Boolean
    Dim hFile                  As Long
    Dim sBuffer                As String
    Dim sReadBuffer            As String * 2048
    Dim lNumberOfBytesRead     As Long
    Dim bDoLoop                As Boolean
    Dim Sum                    As Long
    Dim x                      As Integer

    GetFiles = True

    If vMode = 0 Then  '
        Transfer = FTP_TRANSFER_TYPE_ASCII
    Else
        Transfer = FTP_TRANSFER_TYPE_BINARY
    End If
    InProgress = True
    hFile = FtpOpenFile(hConnection, Trim(strFile), GENERIC_READ, Transfer, 0)

    If hFile = 0 Then
        MsgBox Err.LastDllError, vbCritical + vbOKOnly, "提示"
        GetFiles = False
        Exit Function
    End If

    Open strNewFile For Binary Access Write As #2

    bDoLoop = True
    StopTransfert = False

     While bDoLoop
        DoEvents
        If StopTransfert = True Then
           Close #2
           Kill strNewFile

           For x = 1 To 10000
               DoEvents
           Next x
           GetFiles = False
           Call ResetPB
           GoTo StopGetFiles
        End If

        sReadBuffer = vbNullChar
        bDoLoop = InternetReadFile(hFile, sReadBuffer, Len(sReadBuffer), lNumberOfBytesRead)
        sBuffer = sBuffer & Left$(sReadBuffer, lNumberOfBytesRead)
        If Not CBool(lNumberOfBytesRead) Then bDoLoop = False
        Sum = Sum + lNumberOfBytesRead
        Call ProgressBar(lngFileSize, Str(Sum), strFile)
        Put #2, , sBuffer

        sBuffer = ""
     Wend

StopGetFiles:
   Close #2
   InternetCloseHandle (hFile)

End Function

中的sBuffer & Left$(sReadBuffer, lNumberOfBytesRead)问题，应为byte，但我不会改，请赐教！谢谢 --------------------编程问答-------------------- 试试
sBuffer & LeftB(sReadBuffer, lNumberOfBytesRead) --------------------编程问答-------------------- 谢谢！但还是不行！各位帮帮忙 --------------------编程问答-------------------- 不知道解决问题了吗？ --------------------编程问答-------------------- 不管你解决与否，你的问题至少给了我资源的出处，我找到了答案，和你共享，也和其他人共享一下。参考了“InternetReadFile如何正确读取二进制文件 - pl2597758的专栏”
1.首先声明要修改为byte
Public Declare Function InternetReadFileByte Lib "wininet.dll" Alias "InternetReadFile" _
     (ByVal hFile As Long, _
      ByRef sBuffer As Byte, _
      ByVal lNumberOfBytesToRead As Long, _
      lNumberOfBytesRead As Long) As Integer
2.在你这段代码里，修改的如下
（1）   Dim sReadBuffer(1023)      As Byte
（2）  bDoLoop = InternetReadFileByte(hFile, sReadBuffer(0), 1024, lNumberOfBytesRead)
      'sBuffer = sBuffer & Left$(sReadBuffer, lNumberOfBytesRead)
      If Not CBool(lNumberOfBytesRead) Then bDoLoop = False
      'Sum = Sum + lNumberOfBytesRead
      Call ProgressBar(lngFileSize, Str(Sum), strFile)
      Put #2, , sReadBuffer
      'sBuffer = ""
各位试试吧。 --------------------编程问答-------------------- 'Sum = Sum + lNumberOfBytesRead
改为
Sum = Sum + lNumberOfBytesRead
否则进度条无显示。

补充：VB ,  API