VB.NET

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.

VB.NET

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 New Chilkat.SCard

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


Dim stReaders As New Chilkat.StringTable
success = scard.ListReaders(stReaders)
If (success = False) Then
    Debug.WriteLine(scard.LastErrorText)
    Exit Sub
End If


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

    Debug.WriteLine(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
            Debug.WriteLine("ReaderStatus: " & scard.ReaderStatus)
            Debug.WriteLine("CardAtr: " & scard.CardAtr)
            Debug.WriteLine("ActiveProtocol: " & scard.ActiveProtocol)
        Else
            Debug.WriteLine(scard.LastErrorText)
            Debug.WriteLine("CheckStatus failed.")
        End If


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

    Debug.WriteLine("---------------------------------------")
    i = i + 1
End While

' 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
    Debug.WriteLine(scard.LastErrorText)
End If