VB6 - Declaring and calling C DLL with pointers

Question

I have an old C DLL I use to call from Ruby, but now I need to call it from VB6 and I can\'t figure out the correct way to do so.

Here is the header for the function

Answer 1

Air code

Private Declare DecrunchGetLength Alias "Decrunch" Lib "somedll.DLL" (ByRef src As Byte, ByVal nullptr As Long, ByVal SrcLength As Long) As Long 

Private Declare Decrunch Alias "Decrunch" Lib "somedll.DLL" (ByRef src As Byte, ByRef dest As Byte, ByVal SrcLength As Long) As Long 

Dim destLen As Long
 Dim src(0 To 9) As Byte 
Dim dest() As Byte 

' get bytes into src somehow 

' get dest length 
destLen = DecrunchGetLen( src(0), 0, 10) 

ReDim dest(0 To destLen - 1) 
destLen = Decrunch( src(0), dest(0), 10) 

Useful links

• Declare statement
• Advanced calling C DLLs from VB5/VB6