[AdamSpeight2008]

This tutorial is on how to create your pack of cards, which you can use a basis for other card games.
It'll touch on the aspects of Object Orientated Design (O.O.D.)
You'll also be using LINQ, RegEx (Regular Expressions) and creating custom sorts.

The Basics
So what is a pack of cards?
A pack of cards is collection of 52 playing cards (minus the jokers).
It can be shuffled, to rearrange to order of the cards.
Playing cards can dealt from it.

So what is a playing cards? What make each playing card unique?
A playing card is a card which is made unique by it face value and suit value.

Object Designs
We know have two objects to design (Playing Card and Deck of Cards)
Lets concentrate on the Playing Card first, as need Playing Cards to build deck.

Coding the Playing Card

Public Class PlayingCard
 Dim Suits() As String = {"S", "D", "C", "H"}
 Dim Faces() As String = {"2", "3", "4", "5", "6", "7", "8", "9", "T", "J", "Q", "K", "A"}
 Private mFace As String
 Private mSuit As String
 Protected cv As Integer = 0
 Protected sv As Integer = 0

 Public ReadOnly Property Suit() As String
  Get
   Return mSuit
  End Get
 End Property

 Public ReadOnly Property Face() As String
  Get
   Return mFace
  End Get
 End Property

 Public ReadOnly Property CardValue() As Integer
  Get
   Return cv
  End Get
 End Property

 Public ReadOnly Property SuitValue() As Integer
  Get
   Return sv
  End Get
 End Property

You'll see have defined four (4) read-only properties (Suit, Face, FaceValue, SuitValue).

Why read-only? Cos we don't won't people changing them have been set.
So how do we set them in the first place? We set them when create (initialization) a new playing card object.
Which is what the next sub routine does.

 Public Sub New(ByVal tSuit As String, ByVal tFaceValue As String)
  mFace = tFaceValue
  mSuit = tSuit
  cv = Array.IndexOf(Of String)(Faces, mFace) '+ 1
  sv = Array.IndexOf(Of String)(Suits, mSuit) ' + 1
 End Sub

The next function returns a string contain the value of the card e.g. D4 for Four of Diamonds.

 Public Overrides Function ToString() As String
  Return mSuit & mFace
 End Function

We don't want to just display text strings for each card, lets draw them a cards.
Note: Each card is a gif contained within a folder called \cards_gif, which must be in the some folder as the executable

 Public Sub DrawCard(ByRef g As Graphics, ByRef x As Integer, ByRef y As Integer)
  g.CompositingQuality = Drawing2D.CompositingQuality.GammaCorrected
  g.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
  g.SmoothingMode = Drawing2D.SmoothingMode.HighQuality
  g.DrawImage(New System.Drawing.Bitmap(System.Windows.Forms.Application.StartupPath & "\cards_gif\" & Me.ToString & ".gif"), x, y, 46, 64) '71, 96)
 End Sub

We also want to be able to compare our playing card and since the VB.Net Framework doesn't know how to sort card, we have tell it.

 Public Class CardComparer
  Implements IComparer(Of PlayingCard)
  Public Function Compare(ByVal x As PlayingCard, ByVal y As PlayingCard) As Integer Implements System.Collections.Generic.IComparer(Of PlayingCard).Compare
   Dim RANKS() As String = {"A", "K", "Q", "J", "T", "9", "8", "7", "6", "5", "4", "3", "2"}
   Dim xi = Array.IndexOf(Of String)(RANKS, CStr(x.ToString)(1))
   Dim Yi = Array.IndexOf(Of String)(RANKS, CStr(y.ToString)(1))
   Return xi.CompareTo(Yi)
  End Function
 End Class
End Class

Coding the Deck of Cards

Public Class DeckOfCards
 Dim r As New Random(Now.Millisecond)
 Dim mDeck As New List(Of PlayingCard)
 Dim Suits() As String = {"S", "D", "C", "H"}
 Dim Faces() As String = {"2", "3", "4", "5", "6", "7", "8", "9", "T", "J", "Q", "K", "A"}

 Public Sub New()
  For Each Suit As String In Suits
   For Each Face As String In Faces.Reverse
	mDeck.Add(New PlayingCard(Suit, Face))
   Next
  Next
 End Sub

We have just created a collection of playing cards. Simple isn't when you O.O.D. principles.
So we have a deck of cards but at the moment we can't do much with it, lets change that.

 Public Sub ShuffleCards()
  Dim rc As PlayingCard
  Dim rn As Integer
  For i As Integer = 0 To 52
   rn = r.Next(0, 51) Mod mDeck.Count
   rc = mDeck(rn)
   mDeck.RemoveAt(rn)
   mDeck.Add(rc)
  Next
 End Sub

Now it can be shuffled.

 Public ReadOnly Property TakeCard() As PlayingCard
  Get
   Dim RemovedCard As PlayingCard = mDeck(0)
   mDeck.RemoveAt(0)
   Return RemovedCard
  End Get
 End Property

Now we can take a card from the deck.

The next property displays the state of the deck. So if you want to make cheating harder remove it.

 Public ReadOnly Property DeckState() As String
  Get
   Dim d As String = ""
   For Each m As PlayingCard In mDeck
	d &= m.ToString
   Next
   Return d
  End Get
 End Property

End Class

Putting the deck of cards to use.
So now we have deck of playing cards let do something with them.
How about create a several hand of cards and sort them as if they were poker hands, with the best hand first.

Coding the hands

Public Class HandOfCards
 Protected mHand As List(Of PlayingCard)

 Public Sub New()
  mHand = New List(Of PlayingCard)
 End Sub

 Public Sub AddCard(ByVal card As PlayingCard)
  If mHand.Count = 5 Then Exit Sub
  mHand.Add(card)
 End Sub

So now it is possible to place cards into a hand.

 Public Function Card(ByRef index As Integer) As PlayingCard
  If index < 0 Or index > 4 Then Return Nothing
  Return mHand(index)
 End Function

Refer to a card by its position in a hand.

Sort the hand by using Card Comparer we wrote earlier.

 Public Sub SortHand()
  mHand.Sort(New PlayingCard.CardComparer)
 End Sub

 Public Overrides Function ToString() As String
  Dim s As String = ""
  mHand.Sort(New PlayingCard.CardComparer)
  For Each pc As PlayingCard In mHand
   s &= pc.ToString
  Next
  Return s
 End Function

 Public Sub DrawHand(ByRef g As Graphics, ByRef x As Integer, ByRef y As Integer)
  For i As Integer = 0 To 4
   mHand(i).DrawCard(g, 10 + 25 * i, y)

  Next
  g.DrawString(NameOfHand, New Font("Tahoma", 16, FontStyle.Regular, GraphicsUnit.Pixel, 0), Brushes.Black, 175, y + 25)
 End Sub

Also we can return the hand as a string or display it on a graphic surface.

The next function is a little complex, as it works out the distribution of the face values in the hand. Orders them by quantity (most to least), them by face value.
To do this we use LINQ.

 Public Function ValueOfHand() As String
  Dim DictionaryOfAlpha As New Dictionary(Of Char, Integer)
  Dim Alpha() As Char = "MLKJIHGFEDCBA"
  For I As Integer = 0 To Alpha.Count - 1 : DictionaryOfAlpha.Add(Alpha(I), 0) : Next
  For i As Integer = 0 To mHand.Count - 1 : DictionaryOfAlpha(Alpha(mHand(i).CardValue)) += 1 : Next
  Dim ReorderDictionary As IEnumerable = From DictionaryEntry In DictionaryOfAlpha _
						  Select DictionaryEntry _
						  Order By DictionaryEntry.Value Descending, _
						  DictionaryEntry.Key Ascending
  ValueOfHand = ""
  For Each Entry In ReorderDictionary : ValueOfHand &= Strings.StrDup(Entry.Value, Entry.Key) : Next
 End Function

The next function returns a string containing the distribution of card suits in the hand.

 Public Function SuitValueOfHand() As String
  Dim n(3) As Integer
  For i As Integer = 0 To mHand.Count - 1
   n(mHand(i).SuitValue) += 1
  Next
  SuitValueOfHand = n(0).ToString & n(1).ToString & n(2).ToString & n(3).ToString
  Return SuitValueOfHand
 End Function

The next the Rank Distribution.

 Public Function RankDistrubtion() As String
  Dim n(12) As Integer
  For i As Integer = 0 To mHand.Count - 1 : n(mHand(i).CardValue) += 1 : Next
  RankDistrubtion = ""
  For i As Integer = 12 To 0 Step -1 : RankDistrubtion &= n(i).ToString : Next
  Return RankDistrubtion
 End Function

The next function returns a string containing the poker hand of the hand of cards (eg Royal Flush or Three of a Kind etc)

 Public Function NameOfHand() As String
  Dim f As String = RankDistrubtion()
  Dim s As String = SuitValueOfHand.ToString
  Select Case True
   Case System.Text.RegularExpressions.Regex.Match(f, "0*111110*").Success
	' Contains 5 Consectative Cards
	If System.Text.RegularExpressions.Regex.Match(s, "0*50*").Success Then
	 ' Contains 5 Cards of same Suit
	 If f = "1111100000000" Then
	  Return "01. Royal Flush"
	 Else
	  Return "02. Straight Flush"
	 End If
	Else
	 Return "06. Straight"
	End If
   Case System.Text.RegularExpressions.Regex.Match(f, "[01]*4[01]*").Success : Return "03. Four of a Kind"
   Case System.Text.RegularExpressions.Regex.Match(f, "(0*20*30*)|(0*30*20*)").Success() : Return "04. Full House"
   Case System.Text.RegularExpressions.Regex.Match(f, "0*10*10*10*10*10*").Success
	If System.Text.RegularExpressions.Regex.Match(s, "0*50*").Success Then Return "05. Flush"
   Case System.Text.RegularExpressions.Regex.Match(f, "[01]*3[01]*").Success : Return "07. Three Of a Kind"
   Case System.Text.RegularExpressions.Regex.Match(f, "[01]*2[01]*2[01]*").Success() : Return "08. Two Pair"
   Case System.Text.RegularExpressions.Regex.Match(f, "[01]*2[01]*").Success : Return "09. Pair"
  End Select
  Return "10. High Card"
 End Function

This is achieved by looking for patterns in the distribution of both the card values of suits. The best object to use for pattern matching is a RegEx or Regular Expression.
So a royal flush is SASKSQSJST or 1111100000000 for the value distribution and "0*50*" for the suit distribution.

Since VB.Net doesn't know how to compare to hands of cards, we have to tell it how.

 Public Class HandComparer
  Implements IComparer(Of HandOfCards)
  Public Function Compare(ByVal x As HandOfCards, ByVal y As HandOfCards) As Integer Implements System.Collections.Generic.IComparer(Of HandOfCards).Compare
   Dim c As Integer = x.NameOfHand.Substring(0, 2).CompareTo(y.NameOfHand.Substring(0, 2))
   Select Case c
	Case -1, 1 : Return c
	Case 0 : Return String.Compare(x.ValueOfHand, y.ValueOfHand)
   End Select
  End Function
 End Class
End Class

The Demonstration Form

Create a windows form. Add button then insert this code.

Public Class Form1
 Dim TheDeck As DeckOfCards
 Dim Hands(NumberOfHands - 1) As HandOfCards
 Const NumberOfHands As Integer = 10
 

 Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
  If TheDeck IsNot Nothing Then
   For i = 0 To NumberOfHands - 1
	Hands(i).DrawHand(e.Graphics, 25, 25 + i * 65)
   Next
  End If


 End Sub


 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  Console.WriteLine("--------")


  TheDeck = New DeckOfCards
  TheDeck.ShuffleCards()
  TheDeck.ShuffleCards()
  'TheDeck.ShuffleCards()
  ' TheDeck.ShuffleCards()
  For i = 0 To NumberOfHands - 1
   Hands(i) = New HandOfCards
   For c As Integer = 0 To 4
	Hands(i).AddCard(TheDeck.TakeCard)
   Next
   Hands(i).SortHand()
  Next
  Array.Sort(Hands, New HandOfCards.HandComparer)
  For i = 0 To NumberOfHands - 1
   Console.WriteLine("{0}" & vbTab & "[{1}] = {2}" & vbTab & " {3}" & vbTab & "[{4}]" & vbTab & " ({5})", i + 1, Hands(i).ToString, Hands(i).SuitValueOfHand, Hands(i).RankDistrubtion, Hands(i).NameOfHand, Hands(i).ValueOfHand)
  Next
  'Console.WriteLine("Deck [{0}]", TheDeck.DeckState)
  'Console.WriteLine("Deck [{0}]", TheDeck.DeckState)
  'TheDeck.ShuffleCards()
  'Console.WriteLine("Deck [{0}]", TheDeck.DeckState)
  Me.Refresh()
 End Sub
End Class

Run.

So now you're Poker Hand Sorting Code Ninja

Project Files:  PlayingCards.zip (173.67K)
Number of downloads: 4979

[jimdandy75]

WOW!!!!! That is awesome..... Thanks
I see alot of card game questions on the boards they should be directed here.
I tried tweeking this a little to see if I could get it to deal out a 7 card hand and
return the best 5 card poker hand, like in Texas Hold Em. But my coding skills are
weak Could you possibly extend this tutorial to show that?
Pretty, pretty please????

This post has been edited by jimdandy75: 03 May 2009 - 11:25 AM

[AdamSpeight2008]

Texas-Holdem like play.


Add this to the DeckOfCards Class

 Public ReadOnly Property CardsLeft() As Integer
  Get
   Return mDeck.Count

  End Get
 End Property

modified DrawHand also.

 Public Sub DrawHand(ByRef g As Graphics, ByRef x As Integer, ByRef y As Integer,optional ByRef t As Boolean=True)
  For i As Integer = 0 To mHand.Count - 1
   mHand(i).DrawCard(g, 10 + 25 * i, y)

  Next
  If t Then g.DrawString(NameOfHand, New Font("Tahoma", 16, FontStyle.Regular, GraphicsUnit.Pixel, 0), Brushes.Black, 175, y + 25)
 End Sub

Create a new project or form, if you're creating a new form in the tutorial project remember to set the startup form to the new one

Add a couple of buttons;- Hand (Players Cards) & Dealt (River cards)

Public Class TexasHoldem
 Dim TheDeck As DeckOfCards
 Dim Hands(NumberOfHands - 1) As HandOfCards
 Dim Dealt As HandOfCards
 Dim BestHandIs As HandOfCards



 Const NumberOfHands As Integer = 1
 Dim a As New List(Of String)
 Dim b As New List(Of String)

 Private Sub TexasHoldem_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
  MchooseN(3, 0, 4, a)
  MchooseN(4, 0, 4, b)

 End Sub

 Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
  If TheDeck IsNot Nothing Then
   For i = 0 To NumberOfHands - 1
	Hands(i).DrawHand(e.Graphics, 25, 100 + i * 65, False)
	If Dealt IsNot Nothing Then Dealt.DrawHand(e.Graphics, 25, 175 + i * 65, False)
	If lh IsNot Nothing AndAlso lh.Count > 0 Then
	 BestHandIs.DrawHand(e.Graphics, 25, 250 + i * 65, True)
	End If
   Next
  End If


 End Sub

 Private Function BestHand(ByRef meCards As HandOfCards, ByRef rc As HandOfCards) As HandOfCards
  If meCards Is Nothing Then Return Nothing
  If rc Is Nothing Then Return Nothing

  lh.Clear()

  Dim an As HandOfCards
  For Each aa As String In a
   an = New HandOfCards

   For i As Integer = 0 To 2
	an.AddCard(rc.Card(Integer.Parse(aa(i))))
   Next
   an.AddCard(meCards.Card(0))
   an.AddCard(meCards.Card(1))
   an.SortHand()
   lh.Add(an)

  Next
  For j As Integer = 0 To 1
   For Each aa As String In b
	an = New HandOfCards

	For i As Integer = 0 To 3
	 an.AddCard(rc.Card(Integer.Parse(aa(i))))
	Next
	an.AddCard(meCards.Card(j))
	an.SortHand()
	lh.Add(an)
   Next
  Next
  lh.Sort(hc)

  Return lh(0)

 End Function

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  If TheDeck Is Nothing Then newdeck()

  If TheDeck.CardsLeft < 5 Then newdeck()

  TheDeck = New DeckOfCards
  TheDeck.ShuffleCards()
  TheDeck.ShuffleCards()
  For i As Integer = 0 To NumberOfHands - 1
   Hands(i) = New HandOfCards

   For c As Integer = 0 To 1
	Hands(i).AddCard(TheDeck.TakeCard)
   Next
   Hands(i).SortHand()

  Next
  BestHandIs = BestHand(Hands(0), Dealt)

  Me.Refresh()

 End Sub
 Private Sub newdeck()

  TheDeck = New DeckOfCards
  TheDeck.ShuffleCards()
  TheDeck.ShuffleCards()

 End Sub

 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
  If TheDeck.CardsLeft < 5 Then newdeck()
  Dealt = New HandOfCards

  For i As Integer = 0 To 4
   Dealt.AddCard(TheDeck.TakeCard)
  Next
  Dealt.SortHand()
  BestHandIs = BestHand(Hands(0), Dealt)

  Me.Refresh()

 End Sub
 Dim hc As New HandOfCards.HandComparer
 Dim lh As New List(Of HandOfCards)

 Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
  BestHandIs = BestHand(Hands(0), Dealt)
  Me.Refresh()

 End Sub


 Private Sub MchooseN(ByRef N As Integer, ByRef first_allowed As Integer, ByRef last_allowed As Integer, ByRef solutions As List(Of String))
  Dim i As Integer = 0
  Dim txt As New System.Text.StringBuilder
  Dim partial_solutions As List(Of String)
  Dim fapo As Integer = first_allowed + 1
  Dim lmf As Integer = last_allowed - first_allowed + 1
  ' Change spacer to alter character between numbers.
  Const Spacer As String = ""
  ' If N < 1, we don't need to pick any more items.
  ' If N > last_allowed - first_allowed + 1, there are too few items for a solution.
  ' If N = last_allowed - first_allowed + 1,' all the items must be in the solution.
  Select Case True
   Case N < 1 ' We don't need to pick any more, Do nothing.
   Case N > lmf ' There are not enough items. Do nothing.
   Case N = lmf
	' All the items must be in the solution.
	txt.Append(Format$(first_allowed))
	For i = fapo To last_allowed
	 txt.Append(Format$(i) & Spacer)
	Next i
	solutions.Add(txt.ToString)
   Case Else
	'Get solutions containing first_allowed.
	partial_solutions = New List(Of String)
	If N = 1 Then
	 partial_solutions.Add("")
	Else
	 MchooseN(N - 1, fapo, last_allowed, partial_solutions)
	End If
	' Add first_allowed to make the full solutions.
	For i = 0 To partial_solutions.Count - 1
	 solutions.Add(Format$(first_allowed) & partial_solutions(i))
	Next i
	' Get solutions not containing first_allowed.
	partial_solutions = New List(Of String)
	MchooseN(N, fapo, last_allowed, partial_solutions)
	' Add these to the solutions.
	solutions.AddRange(partial_solutions)
  End Select
 End Sub
End ClassEnd Class

Some of you may have noticed that this is only a players hand.
It is left as an exercise for the reader to extend to multiple players.

This post has been edited by AdamSpeight2008: 03 May 2009 - 05:31 PM

[jimdandy75]

Yup, you da man!!!!! Thank you, it works great

[DataPriest]

Good work man. Loved the code.

[Randomluck]

First, thanks for the example, it is very nice. Second, I do have a question on how to proceed with the following example:

Taking this example:
We have the class of "PlayingCard". What if we extend the class to two new classes "Class CardA inherits PlayingCard" and "Class CardB inherits PlayingCards". Each class has an additional distinct set of properties.

Now, I'd like to reuse the DeckOfCards object (for the shuffle and drawcards function), but I'd like CardA and a second DeckOfCards using CardB.

When I've tried this code at home VS has thrown an "The type initializer for 'BSGEngine.modGlobals' threw an exception." error and crashes. Is what I'm talking about feasible or would I need a "DeckOfCards" object specified for each class of playing Cards I create?

Thanks and I appreciate your input.

[AdamSpeight2008]

See this post for solution to Randomluck's problem.

[Peanut373]

I appreciate the tutorial but I am getting a couple of errors when I run the program. Why is this?

[tguns17]

Adam,

I have been searching for code on card games and I feel like I've been everywhere. I really liked the code you provide at http://www.dreaminco...-playing-cards/
but for some reason I must not be entering it into vb.net correctly. I have also tried to download the PlayingCards.zip file and that didn't work either. I am very new to vb and am trying to program video poker card games. Can you send me the files that you used so that I can see exactly how to put these into a visual basic. Thanks.

[ankitj86]

Hi Adam,

Awesome Work!!!! I have been looking for a poker game logic for a long time and your code works BEAUTIFULLY. I am looking to do some modifications in the game, but I am fairly new to VB coding.

I have placed two containers (picture-boxes) on the form and I want the user two enter the two cards. Now, I want the program to deal out 5 random cards from the deck, after excluding the two cards already entered. Finally I am looking it to calculate all 7 cards for the hand.
But I am not sure what all modifications to the code it would need.

Please help me do these changes. I appreciate your help.

Thanks

[colossus1958]

[quote name='AdamSpeight2008' date='28 November 2008 - 02:50 PM' timestamp='1227909048' post='475888']
This tutorial is on how to create your pack of cards, which you can use a basis for other card games.
It'll touch on the aspects of Object Orientated Design (O.O.D.)
You'll also be using LINQ, RegEx (Regular Expressions) and creating custom sorts...

I really like this code. Short and to the point. If you are looking for help on coding poker games. Solitaire games are another story however. I have been searching on-line for over a year now, and while I've found bits and pieces that have helped me out (drag-and-drop, shuffle, etc.) I have yet to see a tutorial based around the creation of a solitaire game. I haven't given up yet. Maybe you know some places to go that I don't. (I have been through Google with every variation I could think of.)

[Blind_Geek81]

Your tutorial kicks butt!!!!
This will help me SO much with my Blackjack game! It is version 4 of one of my finals! I've been switching between C# and VB since the day I got the assignment, and I've gotta say, my VB project is going much smoother than my C# ones have! Now if only I could translate my console game to a windows form...yikes!!

[PickyBiker]

This is terrific. I did notice that if the NumberOfDecks constant is made greater than 10, something breaks. I am trying to find out why.

PickyBiker

PickyBiker, on 12 January 2012 - 02:04 PM, said:

This is terrific. I did notice that if the NumberOfDecks constant is made greater than 10, something breaks. I am trying to find out why.

PickyBiker

I meant NumberOfHands constant

[PickyBiker]

PickyBiker, on 12 January 2012 - 02:05 PM, said:

This is terrific. I did notice that if the NumberOfDecks constant is made greater than 10, something breaks. I am trying to find out why.

PickyBiker

PickyBiker, on 12 January 2012 - 02:04 PM, said:

This is terrific. I did notice that if the NumberOfDecks constant is made greater than 10, something breaks. I am trying to find out why.

PickyBiker

I meant NumberOfHands constant

Figured it out. After 10 hands have been dealt, there are not enough cards left in the deck for another hand so after the 2nd card in the 11th hand is dealt, the attempt to take another card fails.... Duh!

[ana.O]

Great tutorial!!!

How implemente and use jokers??!!

Thanks in advance!