Serial port communication in VC ++
when reading data through a serial port
VARIANT data;
BSTR k;
if(m_mscom.GetCommEvent() == 2)
{
data = m_mscom.GetInput();
k = data.bstrVal;
}
What is BSTR k;
and what do you mean k=data.bstrVal
? What is it bstrVal
?
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manoj
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2 answers
BSTR and VARIANT are used data types in COM. In fact, VARIANT is a container that can contain any COM data type.
In your case, GetInput () returns a VARIANT containing the buffer as BSTR, so bstrVal must be used to retrieve it.
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Dmitry Khalatov
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BSTR is a pointer to a Unicode character (only the type of character that can contain a Unicode character). data.bstrVal converts the variant to BSTR.
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yesraaj
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