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ActiveX Refnum and GUIDs

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Hi there,

I looked for a way to get the IID from an ActiveX Refnum.

So I looked at the TypeDescriptor and fortunately

it contains not only the IID but also the CLSID and TypeLibrary

of the underlying interface.


But I'm still looking for a way to Check whether my Input Variant

contains an ActiveX Refnum. I can check for Refnum,

but it must be an _ActiveX_ Refnum, else my VI has to return an error.

Currently I'm checking the length of the TD but I don't think that's

an error-proof solution.

Has anyone a better idea?


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If you still want to test the variant type before trying the variant casting, the 6th byte in the typedesc will tell you the refnum type (value 7 is for ActiveX Automation references). Though I do agree the other way is probably faster.



Thank you!:thumbup1:

I already noticed that this byte must have something to do with the Refnum type

but I was unsure. Is there any documentation about that? The LV documentation tells something about TDs of plain types but not much about Refnum TDs...

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