Subject:
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Re: Spirit.ocx in VC++
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Newsgroups:
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lugnet.robotics
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Date:
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Sun, 5 Mar 2000 14:49:05 GMT
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Viewed:
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776 times
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Hi Steve,
On Sun, 5 Mar 2000 01:19:22 GMT, you wrote:
> Actually, the datatype is VARIANT, which is a typedef around a struct
> that's used to support a slew of datatypes in a single type. The struct
> contains a member "vt" that describes the datatype of the data that's
> stored in the variant. Based on the value of "vt", the actual data will
> have a name corresponding to the type.
That's right. In the case of the datalog the type of the "vt" is
(VT_ARRAY | VT_I2), that is an array of 2-byte integers.
> So, a possible chunk of code for checking the return from UploadDatalog
> might look like this:
>
> VARIANT retVariant = UploadDatalog(From, Size);
> if (retVariant.boolVal == VARIANT_TRUE)
> {
> // it worked!
> }
> else
> {
> // it failed!
> }
>
> Anyway, I hope this helps.
Thank you very much, Steve. Your message was helpful for me to
understand I'm in the right way to the solution.
Anyway, I think I need to explain better what is my problem.
I _successfully_ upload the datalog from the RCX into a VARIANT
variable, but I do not succeed in extracting the array of logged
values from that variable. I am surely doing something wrong with
the SafeArrayAccessData method.
Here follows the code I wrote to save the raw logged data in
the test.dat file:
//----------------------- cut here -----------------------------
VARIANT datalog;
short *loggedData;
CFile f;
f.Open( "test.dat", CFile::modeCreate | CFile::modeWrite);
VariantInit(&datalog);
datalog = m_ctrlego.UploadDatalog(1, 10);
if (datalog.vt == (VT_ARRAY | VT_I2))
{
SafeArrayAccessData(datalog.parray, (void HUGEP* FAR*)&loggedData);
SafeArrayUnaccessData(datalog.parray);
f.Write(loggedData, datalog.parray->rgsabound->cElements);
}
f.Close();
//----------------------- cut here -----------------------------
The result is by far different from the datalog uploaded
using RCXcc, and I really can't understand why!
Bye,
Antonio
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Message has 1 Reply:
 | | Re: Spirit.ocx in VC++ [DAT]
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| Hi Steve, Len and All, I was closer to the solution than I thought! The code I posted this morning was correct. What I missed was the format of the datalog, which is very hard to understand from the docs of spirit.ocx. After hacking around for a (...) (25 years ago, 5-Mar-00, to lugnet.robotics)
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Message is in Reply To:
| | Re: Spirit.ocx in VC++
|
| Antonio, Actually, the datatype is VARIANT, which is a typedef around a struct that's used to support a slew of datatypes in a single type. The struct contains a member "vt" that describes the datatype of the data that's stored in the variant. Based (...) (25 years ago, 5-Mar-00, to lugnet.robotics)
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