B4X

PC/SC Check the Status of each Smart Card Reader (and USB token)

See more SCard Examples

Demonstrates how to list the smart card readers and USB tokens connected to the computer, and check the status of each.

Note: This functionality was introduced in Chilkat v9.5.0.87.

B4X

Dim success As Boolean = False

'  This example requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

Dim scard As ChilkatSCard
scard.Initialize("scard")

'  First establish a context to the PC/SC Resource Manager
success = scard.EstablishContext("user")
If success = False Then
    Log(scard.LastErrorText)
    Return
End If


Dim stReaders As ChilkatStringTable
stReaders.Initialize
success = scard.ListReaders(stReaders)
If success = False Then
    Log(scard.LastErrorText)
    Return
End If


Dim numReaders As Int = stReaders.Count
Dim i As Int = 0
Do While i < numReaders
    Dim reader As String = stReaders.StringAt(i)

    Log(i & ": " & reader)

    '  Connect to this reader.
    If scard.Connect(reader, "shared", "no_preference") = True Then

        '  Check the status to get the reader state, active protocol, and card ATR (if a card is inserted).
        If scard.CheckStatus = True Then
            Log("ReaderStatus: " & scard.ReaderStatus)
            Log("CardAtr: " & scard.CardAtr)
            Log("ActiveProtocol: " & scard.ActiveProtocol)
        Else
            Log(scard.LastErrorText)
            Log("CheckStatus failed.")
        End If


        '  Disconnect from this reader.
        success = scard.Disconnect("leave")
    Else
        Log(scard.LastErrorText)
        Log("Connect failed.")
    End If

    Log("---------------------------------------")
    i = i + 1
Loop

'  Sample output:

'  0: Alcor Micro USB Smart Card Reader 0
'  ReaderStatus: specific
'  CardAtr: 3B7F96000080318065B0855956FB120FFE829000
'  ActiveProtocol: T0
'  ---------------------------------------
'  1: Generic Smart Card Reader Interface 0
'  ReaderStatus: specific
'  CardAtr: 3BFC180000813180459067464A00641606F2727E00E0
'  ActiveProtocol: T1
'  ---------------------------------------
'  2: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
'  ReaderStatus: specific
'  CardAtr: 3BDF96FF8131FE455A018048494443313158587300011B09
'  ActiveProtocol: T1
'  ---------------------------------------

'  Applications should always release the context when finished.
success = scard.ReleaseContext
If success = False Then
    Log(scard.LastErrorText)
End If