Passing Strings

Hi,

I'm writing a DLL that needs to be able to call back into my VB app with various information. One of the functions in the VB app is like this:

Public Sub MyCallBackFunction(byval text as string)

I have passed the address of this function into the DLL, and can call other functions perfectly normally if I don't need to pass them a string, and I can return a string from a function in the DLL using the method below, but I can't call back into my vb app passing a string as one of the parameters.

LPVOID PackVBStr(char * InBuffer)
{
LPVOID OutBuffer ;
int BufLen ;
BufLen = GetvbStringLen(InBuffer);

OutBuffer =(char*)malloc((BufLen*2)+1);
memcpy(OutBuffer,InBuffer,((BufLen*2)+1));
return OutBuffer ;

}


USHORT GetvbStringLen(LPVOID InBuffer)
{
char *t;
int count=0;
int BufLen=0;

t = (char*)InBuffer;

while(count<2)
{
if(*t != '\0')
{
count = 0;
BufLen++;
}
else
{
count++;
}
t++;
}
return(BufLen);
}

LPVOID APIENTRY ReturnString()
{
LPVOID ret = PackVBStr("Hello World");
return ret;
}

Any ideas?

See your thread in the VB forum.

Search this forum, it has been discussed several times. Search especially for BSTR.

I BSTR'ed him up in the other forum :D

That's gotta hurt ;)