How to put Date into VARIANT data type?

[LeanA]

Hi all,



I want to insert a Date type into a VARIANT that will be used by a certain function that needs a Date, but requires a VARIANT* data type.



The function looks something like this:



_variant_t function(_bstr_t FriendlyName, _bstr_t SubjectName, _bstr_t SMSID, VARIANT *StartTime, VARIANT *EndTime)



I can't do anything about the data type because it is a pre-defined function.



I tried doing this, but I get an error when accessing the function:



VARIANT varDate;

VariantInit(&varDate);



COleDateTime mytime(1996,1,1,0,0,0);

varDate = _variant_t(mytime);



Also when accessing the function, I do it like this:



->function(bstrName, bstrName2, bstrID, &varDate, &varDate);



I hope somebody can help me.



Thank you!

[Igor Vartanov]

I tried doing this, but I get an error when accessing the function:

And what error do you get?

[Igor Vartanov]

varDate.vt = VT_DATE;
varDate.date = mytime;

Yep, this is exactly what _variant_t(mytime) is supposed to do.

[LeanA]

Hi Igor and 0xc0000005,

Thanks for replying and the solutions! What worked was:

varDate = _variant_t(mytime, VT_DATE);

Another solution (but with more lines of code):

VARIANT var;
V_VT(&var) = VT_DATE;
V_DATE(&var) = myDateValue;

Thanks again very much!

[ovidiucucu]

Beside the solutions already posted here, the most handy way to deal with VARIANT structures in MFC is to use COleVariant.
Just:

   COleDateTime mytime(1996, 1, 1, 0, 0, 0);
   function(COleVariant(mytime));
   // COleVariant has a constructor which takes const COleDateTime& and an operator LPVARIANT().

A little bit easier, isn't it?

[ovidiucucu]

[ off-topic ]

The Cardinal Rules of Optimization:
1. Do not optimize
2. For experts only: do not optimize yet

Except it's otherwise specified, a clearer/shorter/lesser susceptible for bugs/easier to read and maintain code, has to be preffered to "more efficient" one.