VC++, MSComm.ocx & Null char's

[yorklex]

Below is a snippet from the VCTerm example for VC++.
How can I get null characters into a variant and to transmit out the comm port using this control (example char* Test = "Te\0st\0Te\0st1". I need to be able to do this for a special application interface to DDC controllers. It is really easy with VB but has proven next to impossible with VC++. Can anyone offer a helping hand and possibly an example?

CString ch(nChar);
VARIANT var;
char* Test = "Te\0st\0Te\0st1";



CCommCtrl* pCommCtrl = ((CMainFrame*)
AfxGetMainWnd ())->GetCommCtrl();
if (pCommCtrl->GetPortOpen())
{
var.vt = VT_BSTR;
var.bstrVal = ch.AllocSysString();
pCommCtrl->SetOutput(var);
VariantClear(&var);

Thanks,
Greg K.
York International Corp

 

[programsecrets]

What error are you getting? The first few lines of your code look troublesome:
[ignore]
CString ch(nChar);
VARIANT var;
char* Test = "Te\0st\0Te\0st1";

I think you intend to do this instead:

/* CString allocates the right amount of memory by itself */
CString ch = "Te\0st\0Te\0st1";
VARIANT var;

/* your program doesn't refer to Test, is it needed? */
char* Test = "Te\0st\0Te\0st1";

..
...
....
[/ignore]
So, first try correcting this... I haven't looked at the rest. If you still get an error, tell us what it is.

Hope this helps. ;-)

 

[yorklex]

SysAllocString() will not copy complete strings with null char's embedded I'm guessing because it thinks all strings are null terminated. It was somewhat easier in standard C because you could use memcopy to copy the entire string into a char* and then point to the address of the string to send out to the comm port. There must be some way to do this that I am not thinking of since basic uses that same control and does not question null char's being thrown at it.

Greg K.