zlib/contrib/visual-basic.txt

See below some functions declarations for Visual Basic.

Frequently Asked Question:

Q: Each time I use the compress function I get the -5 error (not enough
   room in the output buffer).

A: Make sure that the length of the compressed buffer is passed by
   reference ("as any"), not by value ("as long"). Also check that
   before the call of compress this length is equal to the total size of
   the compressed buffer and not zero.


From: "Jon Caruana" <jon-net@usa.net>
Subject: Re: How to port zlib declares to vb?
Date: Mon, 28 Oct 1996 18:33:03 -0600

Got the answer! (I haven't had time to check this but it's what I got, and
looks correct):

He has the following routines working:
        compress
        uncompress
        gzopen
        gzwrite
        gzread
        gzclose

Declares follow: (Quoted from Carlos Rios <c_rios@sonda.cl>, in Vb4 form)

#If Win16 Then   'Use Win16 calls.
Declare Function compress Lib "ZLIB.DLL" (ByVal compr As
        String, comprLen As Any, ByVal buf As String, ByVal buflen
        As Long) As Integer
Declare Function uncompress Lib "ZLIB.DLL" (ByVal uncompr
        As String, uncomprLen As Any, ByVal compr As String, ByVal
        lcompr As Long) As Integer
Declare Function gzopen Lib "ZLIB.DLL" (ByVal filePath As
        String, ByVal mode As String) As Long
Declare Function gzread Lib "ZLIB.DLL" (ByVal file As
        Long, ByVal uncompr As String, ByVal uncomprLen As Integer)
        As Integer
Declare Function gzwrite Lib "ZLIB.DLL" (ByVal file As
        Long, ByVal uncompr As String, ByVal uncomprLen As Integer)
        As Integer
Declare Function gzclose Lib "ZLIB.DLL" (ByVal file As
        Long) As Integer
#Else
Declare Function compress Lib "ZLIB32.DLL"
        (ByVal compr As String, comprLen As Any, ByVal buf As
        String, ByVal buflen As Long) As Integer
Declare Function uncompress Lib "ZLIB32.DLL"
        (ByVal uncompr As String, uncomprLen As Any, ByVal compr As
        String, ByVal lcompr As Long) As Long
Declare Function gzopen Lib "ZLIB32.DLL"
        (ByVal file As String, ByVal mode As String) As Long
Declare Function gzread Lib "ZLIB32.DLL"
        (ByVal file As Long, ByVal uncompr As String, ByVal
        uncomprLen As Long) As Long
Declare Function gzwrite Lib "ZLIB32.DLL"
        (ByVal file As Long, ByVal uncompr As String, ByVal
        uncomprLen As Long) As Long
Declare Function gzclose Lib "ZLIB32.DLL"
        (ByVal file As Long) As Long
#End If

-Jon Caruana
jon-net@usa.net
Microsoft Sitebuilder Network Level 1 Member - HTML Writer's Guild Member