From: "Thomas X. Hoban" <thoban at verbalogic dot com>
--------------------------------------------------------------------------------
> Does anyone have a good example that shows how to create a DLL using
> cygwin/gcc and call it using VB .NET? I am specifically interested in an
> example that shows how to pass a String variable. In the example that I
> show below, I am able to call a C function. I can successfully pass a long
> integer. But the string that I pass shows garbage in the called function.
>
> My dll code looks like...
>
>
> (test.c)
>
> #include <stdio.h>
> #include <wtypes.h>
>
> define EXPORT __declspec(dllexport)
>
> EXPORT int myTest(char *s1, long i1) {
>
> printf("Here is the string %s, here is the integer %ld.\n",s1, i1);
>
> }
>
>
I think VB wants stdcall symbols. Add WINAPI to above..
>
> I then compile as follows:
>
> $ gcc -c test.c
> $ gcc -shared -o test.dll test.o
and -Wl,--add-stdcall-alias when building dll to get undecorated symbol too.
I don't have a clue about char* -> STRING marshalling. I would have just used
BSTR.
Danny
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