all my winscard.dll function in vb2010 do not return success/0

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VS2010

Hi All,

I'm doing a interfacing for ACR122u and VB2010. i have search the net and it point to using winscard.dll, i have manage to code all of the function, my scardlistreaders function manage to detect the ACR122u, however my hContext has invalid value, which when i used to scardconnect, the scardconnect return not 0 value. i have place the rfid card on the reader during this test.

can anyone help me to advise the proper way of using winscard dll function in vb2010 and communication to rfid tags. i already check the net. but still my result is still the same.

my sequece is that

scardestablishcontext - return 0 (hcontext has this large value - which i guess is not correct)
scardlistreaders - return 0 (manage to detect the rfid reader installed)
scardconnect - return non 0 value (even there is a rfid card in the reader)
scardtransmit - return 6

my os is window 7, 32 bit

Thanks,