C# Code:

using System;
using System.Drawing;
using System.Runtime.InteropServices;

namespace Cards
{
    /// <summary>
    /// Class wrapper to Cards.dll
    /// </summary>
    public sealed class Card
    {
        #region API Declares
        [DllImport("cards.dll")]
        private static extern bool cdtInit([In] ref int width, [In] ref int height);

        [DllImport("cards.dll")]
        private static extern void cdtTerm();

        [DllImport("cards.dll")]
        private static extern int cdtDrawExt(IntPtr hDC, int x, int y, int dx, int dy,
            int ecsCard, int ectDraw, int clr);

        [DllImport("cards.dll")]
        private static extern int cdtDraw(IntPtr hDC, int x, int y, int ecsCard,
            int ectDraw, int clr);

        [DllImport("cards.dll")]
        private static extern int cdtAnimate(IntPtr hDC, int ecbCardBack, int x, int y, int iState);
        #endregion

        #region fields
        private static int _standardWidth;
        private static int _standardHeight;
        #endregion

        #region Constructor
        static Card()
        {
            bool ret = Card.cdtInit(ref _standardWidth, ref _standardHeight);
            if (!ret)
                throw new ApplicationException("Can't load cards.dll !");

            // free up library when process exits
            AppDomain.CurrentDomain.ProcessExit += new EventHandler(CurrentDomain_ProcessExit);
        }
        #endregion

        #region Public Static Members
        public static void DrawFace(Graphics g, int x, int y, int width, int height, int faceValue, CardSuit suit, Color invertedColor)
        {
            if (faceValue<0 || faceValue>12)
                throw new ArgumentOutOfRangeException("FaceValue", faceValue, "faceValue must be in the range 0 - 12.");

            int cardValue = (int)suit  + faceValue * 4;
            IntPtr hDc = g.GetHdc();
            try
            {
                cdtDrawExt(hDc, x, y, width, height, cardValue, invertedColor!=Color.Empty ? 2 : 0, ConvertColor(invertedColor));
            }
            finally
            {
                g.ReleaseHdc(hDc);
            }
        }
        public static void DrawFace(Graphics g, int x, int y, int width, int height, int faceValue, CardSuit suit)
        {
            DrawFace(g, x, y, width, height, faceValue, suit, Color.Empty);
        }
        public static void DrawFace(Graphics g, int x, int y, int faceValue, CardSuit suit, Color invertedColor)
        {
            if (faceValue<0 || faceValue>12)
                throw new ArgumentOutOfRangeException("FaceValue", faceValue, "faceValue must be in the range 0 - 12.");

            int cardValue = (int)suit  + faceValue * 4;
            IntPtr hDc = g.GetHdc();
            try
            {
                cdtDraw(hDc, x, y, cardValue, invertedColor!=Color.Empty ? 2 : 0, ConvertColor(invertedColor));
            }
            finally
            {
                g.ReleaseHdc(hDc);
            }
        }
        public static void DrawFace(Graphics g, int x, int y, int faceValue, CardSuit suit)
        {
            Card.DrawFace(g, x, y, faceValue, suit, Color.Empty);
        }
        public static void DrawDeck(Graphics g, int x, int y, int width, int height, CardDeck deck)
        {
            IntPtr hDc = g.GetHdc();
            try
            {
                cdtDrawExt(hDc, x, y, width, height, (int)deck, 1, 0);
            }
            finally
            {
                g.ReleaseHdc(hDc);
            }
        }
        public static void DrawDeck(Graphics g, int x, int y, CardDeck deck)
        {
            IntPtr hDc = g.GetHdc();
            try
            {
                cdtDraw(hDc, x, y, (int)deck, 1, 0);
            }
            finally
            {
                g.ReleaseHdc(hDc);
            }
        }
        public static void DrawDeck(Graphics g, int x, int y, int width, int height, Color backgroundColor)
        {
            IntPtr hDc = g.GetHdc();
            try
            {
                cdtDrawExt(hDc, x, y, width, height, (int)CardDeck.CrossHatch, 1, Card.ConvertColor(backgroundColor));
            }
            finally
            {
                g.ReleaseHdc(hDc);
            }
        }
        public static void DrawDeck(Graphics g, int x, int y, Color backgroundColor)
        {
            IntPtr hDc = g.GetHdc();
            try
            {
                cdtDraw(hDc, x, y, (int)CardDeck.CrossHatch, 1, Card.ConvertColor(backgroundColor));
            }
            finally
            {
                g.ReleaseHdc(hDc);
            }
        }
        #endregion

        #region Properties
        /// <summary>
        /// Gets the standard width of the cards.
        /// </summary>
        public static int StandardWidth
        {
            get
            {
                return Card._standardWidth;
            }
        }
        /// <summary>
        /// Gets the standard height of the cards.
        /// </summary>
        public static int StandardHeight
        {
            get
            {
                return Card._standardHeight;
            }
        }
        #endregion

        #region private members
        private static void CurrentDomain_ProcessExit(object sender, EventArgs e)
        {
            Card.cdtTerm();
        }
        private static int ConvertColor(Color c)
        {
            if (c!=Color.Empty)
                return (Convert.ToInt32(c.B) << 16) + (Convert.ToInt32(c.G) << 8) + c.R;
            return 0;
        }
        #endregion
    }

    #region enums
    public enum CardSuit : int
    {
        Clubs = 0,
        Diamonds = 1,
        Hearts = 2,
        Spades = 3
    }
    public enum CardDeck : int
    {
        CrossHatch = 53,
        Weave1 = 54,
        Weave2 = 55,
        Robot = 56,
        Flowers = 57,
        Vine1 = 58,
        Vine2 = 59,
        Fish1 = 60,
        Fish2 = 61,
        Shells = 62,
        Castle = 63,
        Island = 64,
        CardHand = 65,
        The_X = 67,
        The_O = 68
    }
    #endregion
}

VB.NET Code:

Namespace Cards
    ''' <summary>
    ''' Wrapper class for the Cards.dll
    ''' </summary>
    Public NotInheritable Class Card

#Region "API Deceleration"

  <DllImport("cards.dll")> Private Shared Function cdtInit(ByRef width As Integer, ByRef height As Integer) As Boolean
  End Function

  <DllImport("cards.dll")> Private Shared Sub cdtTerm()
  End Sub

  <DllImport("cards.dll")> Private Shared Function cdtDraw(ByVal hDC As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal ecsCard As Integer, ByVal ectDraw As Integer, ByVal clr As Integer) As Integer
  End Function

  <DllImport("cards.dll")> Private Shared Function cdtDrawExt(ByVal hDC As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal dx As Integer, ByVal dy As Integer, ByVal ecsCard As Integer, ByVal ectDraw As Integer, ByVal clr As Integer) As Integer
  End Function

  <DllImport("cards.dll")> Private Shared Function cdtAnimate(ByVal hDC As IntPtr, ByVal ecbCardBack As Integer, ByVal x As Integer, ByVal y As Integer, ByVal iState As Integer)
  End Function

#End Region

#Region "Fields"

    Private Shared _standardWidth As Integer

    Private Shared _standardHeight As Integer

#End Region

#Region "Constructor"

    Shared Sub New()
        Dim ret As Boolean = Card.cdtInit(_standardWidth, _standardHeight)

        If (Not ret) Then
        Throw New ApplicationException("Can't load 'cards.dll'!")
        End If

        ' Free up library when process exits
        AddHandler AppDomain.CurrentDomain.ProcessExit, AddressOf CurrentDomain_ProcessExit
    End Sub

#End Region

#Region "Public Shared Members"

    Public Shared Sub DrawFace(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer, ByVal faceValue As Integer, ByVal suit As CardSuit, ByVal invertedColor As Color)
        If (faceValue < 0 OrElse faceValue > 12) Then
        Throw New ArgumentOutOfRangeException("FaceValue", faceValue, "faceValue must be in the range 0 - 12.")
        End If

        Dim cardValue As Integer = DirectCast(suit, Integer) + faceValue * 4
        Dim hDC As IntPtr = g.GetHdc()

        Try
        cdtDrawExt(hDC, x, y, width, height, cardValue, IIf(invertedColor <> Color.Empty, 2, 0), ConvertColor(invertedColor))
        Finally
        g.ReleaseHdc(hDC)
        End Try
    End Sub

    Public Shared Sub DrawFace(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer, ByVal faceValue As Integer, ByVal suit As CardSuit)
        DrawFace(g, x, y, width, height, faceValue, suit, Color.Empty)
    End Sub

    Public Shared Sub DrawFace(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal faceValue As Integer, ByVal suit As CardSuit, ByVal invertedColor As Color)
        If faceValue < 0 OrElse faceValue > 12 Then
        Throw New ArgumentOutOfRangeException("FaceValue", faceValue, "faceValue must be in the range 0 - 12.")

        Dim cardValue As Integer = DirectCast(suit, Integer) + faceValue * 4
        Dim hDc As IntPtr = g.GetHdc()

        Try
            cdtDraw(hDc, x, y, cardValue, IIf(invertedColor <> Color.Empty, 2, 0), ConvertColor(invertedColor))
        Finally
            g.ReleaseHdc(hDc)
        End Try
        End If
    End Sub

    Public Shared Sub DrawFace(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal faceValue As Integer, ByVal suit As CardSuit)
        Card.DrawFace(g, x, y, faceValue, suit, Color.Empty)
    End Sub

    ' parameter card is a two chars String: the first is the value and the second is the suit
    ' example: "7c" is seven fo club
    Public Shared Sub DrawFace(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal card As String)
        Dim faceValue As Integer = "A23456789JQK".IndexOf(card(0))
        Dim suit As Integer = "cdhs".IndexOf(card(1))
        DrawFace(g, x, y, faceValue, suit, Color.Empty)
    End Sub

    Public Shared Sub DrawDeck(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer, ByVal deck As CardDeck)
        Dim hDc As IntPtr = g.GetHdc()

        Try
        cdtDrawExt(hDc, x, y, width, height, DirectCast(deck, Integer), 1, 0)
        Finally
        g.ReleaseHdc(hDc)
        End Try
    End Sub

    Public Shared Sub DrawDeck(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal deck As CardDeck)
        Dim hDc As IntPtr = g.GetHdc()

        Try
        cdtDraw(hDc, x, y, DirectCast(deck, Integer), 1, 0)
        Finally
        g.ReleaseHdc(hDc)
        End Try
    End Sub

    Public Shared Sub DrawDeck(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer, ByVal backgroundColor As Color)
        Dim hDc As IntPtr = g.GetHdc()

        Try
        cdtDrawExt(hDc, x, y, width, height, DirectCast(CardDeck.CrossHatch, Integer), 1, Card.ConvertColor(backgroundColor))
        Finally
        g.ReleaseHdc(hDc)
        End Try
    End Sub

    Public Shared Sub DrawDeck(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal backgroundColor As Color)
        Dim hDc As IntPtr = g.GetHdc()

        Try
        cdtDraw(hDc, x, y, DirectCast(CardDeck.CrossHatch, Integer), 1, Card.ConvertColor(backgroundColor))
        Finally
        g.ReleaseHdc(hDc)
        End Try
    End Sub

#End Region

#Region "Properties"

    Public Shared ReadOnly Property StandardWith() As Integer
        Get
        Return Card._standardWidth
        End Get
    End Property

    Public Shared ReadOnly Property StandardHeight() As Integer
        Get
        Return Card._standardHeight
        End Get
    End Property

#End Region

#Region "private members"

    Private Shared Sub CurrentDomain_ProcessExit(ByVal sender As Object, ByVal e As EventArgs)
        Card.cdtTerm()
    End Sub

    Private Shared Function ConvertColor(ByVal c As Color) As Integer
        If c <> Color.Empty Then
        Return (Convert.ToInt32(c.B) << 16) + (Convert.ToInt32(c.G) << 8) + c.R
        End If
        Return 0
    End Function

#End Region

#Region "enums"

    Public Enum CardSuit As Integer
        Clubs = 0
        Diamonds = 1
        Hearts = 2
        Spades = 3
    End Enum

    Public Enum CardDeck As Integer
        CrossHatch = 53
        Weave1 = 54
        Weave2 = 55
        Robot = 56
        Flowers = 57
        Vine1 = 58
        Vine2 = 59
        Fish1 = 60
        Fish2 = 61
        Shells = 62
        Castle = 63
        Island = 64
        CardHand = 65
        The_X = 67
        The_O = 68
    End Enum

#End Region

    End Class
End Namespace