C# Signature:

[DllImport("winscard.dll")]
static extern int SCardEstablishContext(uint dwScope, IntPtr pvReserved1, IntPtr pvReserved2, out IntPtr phContext);

VB Signature:

<DllImport("winscard.dll")> _
Public Shared Function SCardEstablishContext(dwScope as UInteger, pvReserved1 as IntPtr,  pvReserved2 as IntPtr, <out>() phContext as IntPtr) As Integer

--- Alternatively ---
Enum SCardScope As UInteger
     <Description("User context and and database operations within the domain of the user")>
     SCARD_SCOPE_USER = 0
     <Description("Terminal context. Calling app must have permissions for database action")>
     SCARD_SCOPE_TERMINAL = 1
     <Description("System context. Calling app must have permissions for database action")>
     SCARD_SCOPE_SYSTEM = 2
End Enum
<DllImport("winscard.dll")> _
Public Shared Function SCardEstablishContext(dwScope as SCardScope, pvReserved1 as IntPtr,  pvReserved2 as IntPtr, ByRef phContext as IntPtr) As Integer
End Function
    Public Shared Function SCardEstablishContext(dwScope as UInteger, pvReserved1 as IntPtr,  pvReserved2 as IntPtr, <out>() phContext as IntPtr) As Integer
    End Function

User-Defined Types:

None.

Notes:

See the sample for other signatures.

in winscard.h

#define SCARD_SCOPE_USER     0    // The context is a user context, and any
                // database operations are performed within the
                // domain of the user.
#define SCARD_SCOPE_TERMINAL 1    // The context is that of the current terminal,
                // and any database operations are performed
                // within the domain of that terminal.  (The
                // calling application must have appropriate
                // access permissions for any database actions.)
#define SCARD_SCOPE_SYSTEM   2    // The context is the system context, and any
                // database operations are performed within the
                // domain of the system.  (The calling
                // application must have appropriate access
                // permissions for any database actions.)

#define SCARD_SCOPE_USER 0 // The context is a user context, and any

                // database operations are performed within the
                // domain of the user.

#define SCARD_SCOPE_TERMINAL 1 // The context is that of the current terminal,

                // and any database operations are performed
                // within the domain of that terminal.  (The
                // calling application must have appropriate
                // access permissions for any database actions.)

#define SCARD_SCOPE_SYSTEM 2 // The context is the system context, and any

                // database operations are performed within the
                // domain of the system.  (The calling
                // application must have appropriate access
                // permissions for any database actions.)

Tips & Tricks:

Please add some!

Sample Code:

This static class contains a single method to detect whether a smartcard is inserted in any reader. Tested under 32- and 64-bit Vista.

    static class SmartCard
    {

    #region Win32
    // WinSCard APIs to be imported.
    [DllImport("WinScard.dll")]
    static extern int SCardEstablishContext(uint dwScope,
    IntPtr notUsed1,
    IntPtr notUsed2,
    out IntPtr phContext);

    [DllImport("WinScard.dll")]
    static extern int SCardReleaseContext(IntPtr phContext);

    [DllImport("WinScard.dll")]
    static extern int SCardConnect(IntPtr hContext,
    string cReaderName,
    uint dwShareMode,
    uint dwPrefProtocol,
    ref IntPtr phCard,
    ref IntPtr ActiveProtocol);

    [DllImport("WinScard.dll")]
    static extern int SCardDisconnect(IntPtr hCard, int Disposition);

    // [DllImport("WinScard.dll")]
    // static extern int SCardListReaderGroups(IntPtr hContext,
    // ref string cGroups,
    // ref int nStringSize);

    [DllImport("WinScard.dll", EntryPoint = "SCardListReadersA", CharSet = CharSet.Ansi)]
    static extern int SCardListReaders(
      IntPtr hContext,
      byte[] mszGroups,
      byte[] mszReaders,
      ref UInt32 pcchReaders
      );

    // [DllImport("WinScard.dll")]
    // static extern int SCardFreeMemory(IntPtr hContext,
    // string cResourceToFree);

    #endregion

    internal static bool SmartCardInserted()
    {
        bool cardInserted = false;
        IntPtr hContext = IntPtr.Zero;

        try
        {

        List<string> readersList = new List<string>();

        int ret = 0;
        uint pcchReaders = 0;
        int nullindex = -1;
        char nullchar = (char)0;

        // Establish context.
        ret = SCardEstablishContext(2, IntPtr.Zero, IntPtr.Zero, out hContext);

        // First call with 3rd parameter set to null gets readers buffer length.
        ret = SCardListReaders(hContext, null, null, ref pcchReaders);

        byte[] mszReaders = new byte[pcchReaders];

        // Fill readers buffer with second call.
        ret = SCardListReaders(hContext, null, mszReaders, ref pcchReaders);

        // Populate List with readers.
        ASCIIEncoding ascii = new ASCIIEncoding();

        string currbuff = ascii.GetString(mszReaders);

        int len = (int)pcchReaders;

        if (len > 0)
        {
            while (currbuff[0] != nullchar)
            {
            nullindex = currbuff.IndexOf(nullchar);   // Get null end character.
            string reader = currbuff.Substring(0, nullindex);
            readersList.Add(reader);
            len = len - (reader.Length + 1);
            currbuff = currbuff.Substring(nullindex + 1, len);
            }
        }

        // We have list of readers, check for cards.
        IntPtr phCard = IntPtr.Zero;
        IntPtr ActiveProtocol = IntPtr.Zero;
        int result = 0;

        foreach (string readerName in readersList)
        {
            try
            {
            result = SCardConnect(hContext, readerName, 2, 3, ref phCard, ref ActiveProtocol);
            if (result == 0)
            {
                cardInserted = true;
                break;
            }
            }
            finally
            {
            SCardDisconnect(phCard, 0);
            }
        }
        }
        finally
        {
        SCardReleaseContext(hContext);
        }

        return cardInserted;

    }
    }

Alternative Managed API:

TODO

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