Hello,
What is the proper way to send byte arrays (or strings for that
matter), from a C DLL to VB? I have tried by prototyping the call in VB
with ByRef Byte[] as a parameter, then treating it in C as a pointer to
unsigned char, and then I tried a memcpy, as well as using pointer
arithmetic to copy over byte per byte.
However, everything I try causes a runtime error regarding the stack
being unbalanced. I am sure I am doing this all wrong, however there
has to be a way to get a piece of memory from C into VB, and I just
can't find it, nor any information on it.
If this is not the proper group, please point me in the right
direction.
Thanks for any help,
Vince
2  1770 
Assuming you are in .NET and calling a C dll, you actually have a
number of options.
If you want bytes, then declare it as a ByVal byte array. Just be sure
you allocate the space (using redim for example) in the .NET side
before calling the C routine.
For text data, you can use a StringBuffer instead of a byte array.
HTH,
Tom
PS - The interop group is probably a better fit for this kind of
question in the future
Vince Castellano wrote:
Hello,
What is the proper way to send byte arrays (or strings for that
matter), from a C DLL to VB? I have tried by prototyping the call in VB
with ByRef Byte[] as a parameter, then treating it in C as a pointer to
unsigned char, and then I tried a memcpy, as well as using pointer
arithmetic to copy over byte per byte.
However, everything I try causes a runtime error regarding the stack
being unbalanced. I am sure I am doing this all wrong, however there
has to be a way to get a piece of memory from C into VB, and I just
can't find it, nor any information on it.
If this is not the proper group, please point me in the right
direction.
Thanks for any help,
Vince
Vince,
>What is the proper way to send byte arrays (or strings for that
matter), from a C DLL to VB? I have tried by prototyping the call in VB
with ByRef Byte[] as a parameter, then treating it in C as a pointer to
unsigned char, and then I tried a memcpy, as well as using pointer
arithmetic to copy over byte per byte.
Try it again, but pass the array ByVal.
Mattias
--
Mattias Sjögren [C# MVP] mattias @ mvps.org http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
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