Many ActiveX ( greed/tree) vendors implement virtual modes for fast data retrieval and flexibility to do some transformations with the data.

It became possible starting from VFP7 to implement interfaces. Just curious whether anyone succeded to make it work exactly how it works in VB for any of the following ActiveX : SharpGrid, ExGrid or anything else.

My problem is for ExGrid, for instance , data instantaneously accesible for scrolling as expected, but none of the numerous editors does work.

I am providing some code to illustrate what I've done , though it is obviously doesn't make a lot of sense ( due to dependancy on a vendor implementation )

main.prg

oevents = NEWOBJECT("ivirtual")

do myform
read events

DEFINE CLASS ivirtual AS Custom

IMPLEMENTS IUnboundHandler IN "exgrid.dll"


PROCEDURE IUnboundHandler_get_ItemsCount() AS NUMBER

RETURN rs.recordcount

ENDPROC

PROCEDURE IUnboundHandler_ReadItem(INDEX AS NUMBER, SOURCE AS VARIANT, ItemHandle AS NUMBER) AS VOID
...
ENDDEFINE

In myform Init
...
thisform.exGrid.UnboundHandler = oevents

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Main difference with VB examples is that VB form itself implements interface
,but not sure whether it contributes to the problem.

TIA
Michael