Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    Friend WithEvents Button4 As System.Windows.Forms.Button
    Friend WithEvents Button5 As System.Windows.Forms.Button
    Friend WithEvents Button6 As System.Windows.Forms.Button
    Friend WithEvents Button7 As System.Windows.Forms.Button
    Friend WithEvents Button8 As System.Windows.Forms.Button
    Friend WithEvents Button9 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.Button4 = New System.Windows.Forms.Button
        Me.Button5 = New System.Windows.Forms.Button
        Me.Button6 = New System.Windows.Forms.Button
        Me.Button7 = New System.Windows.Forms.Button
        Me.Button8 = New System.Windows.Forms.Button
        Me.Button9 = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(8, 8)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(64, 64)
        Me.Button1.TabIndex = 0
        Me.Button1.Tag = "0,0"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(96, 8)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(64, 64)
        Me.Button2.TabIndex = 1
        Me.Button2.Tag = "0,1"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(184, 8)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(64, 64)
        Me.Button3.TabIndex = 2
        Me.Button3.Tag = "0,2"
        '
        'Button4
        '
        Me.Button4.Location = New System.Drawing.Point(184, 88)
        Me.Button4.Name = "Button4"
        Me.Button4.Size = New System.Drawing.Size(64, 64)
        Me.Button4.TabIndex = 5
        Me.Button4.Tag = "1,2"
        '
        'Button5
        '
        Me.Button5.Location = New System.Drawing.Point(96, 88)
        Me.Button5.Name = "Button5"
        Me.Button5.Size = New System.Drawing.Size(64, 64)
        Me.Button5.TabIndex = 4
        Me.Button5.Tag = "1,1"
        '
        'Button6
        '
        Me.Button6.Location = New System.Drawing.Point(8, 88)
        Me.Button6.Name = "Button6"
        Me.Button6.Size = New System.Drawing.Size(64, 64)
        Me.Button6.TabIndex = 3
        Me.Button6.Tag = "1,0"
        '
        'Button7
        '
        Me.Button7.Location = New System.Drawing.Point(184, 168)
        Me.Button7.Name = "Button7"
        Me.Button7.Size = New System.Drawing.Size(64, 64)
        Me.Button7.TabIndex = 8
        Me.Button7.Tag = "2,2"
        '
        'Button8
        '
        Me.Button8.Location = New System.Drawing.Point(96, 168)
        Me.Button8.Name = "Button8"
        Me.Button8.Size = New System.Drawing.Size(64, 64)
        Me.Button8.TabIndex = 7
        Me.Button8.Tag = "2,1"
        '
        'Button9
        '
        Me.Button9.Location = New System.Drawing.Point(8, 168)
        Me.Button9.Name = "Button9"
        Me.Button9.Size = New System.Drawing.Size(64, 64)
        Me.Button9.TabIndex = 6
        Me.Button9.Tag = "2,0"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(264, 246)
        Me.Controls.Add(Me.Button7)
        Me.Controls.Add(Me.Button8)
        Me.Controls.Add(Me.Button9)
        Me.Controls.Add(Me.Button4)
        Me.Controls.Add(Me.Button5)
        Me.Controls.Add(Me.Button6)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Name = "Form1"
        Me.Text = "Tic Tac Toe"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Private Sub btnMoveMade_Click(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles Button1.Click, _
    Button2.Click, Button3.Click, Button4.Click, _
    Button5.Click, Button6.Click, Button7.Click, _
    Button8.Click, Button9.Click
        Dim btnSquareClicked As Button = sender
        Static chrTTT(2, 2) As Char
        Static chrPlayer As Char = "X"
        If btnSquareClicked.Text <> Nothing Then
            MessageBox.Show("Invalid!")
        Else
            btnSquareClicked.Text = chrPlayer
            Dim XOShow = btnSquareClicked.Text
            Dim strIndex As String
            strIndex = btnSquareClicked.Tag
            Dim intX As Integer = Val(strIndex.Chars(0))
            Dim intY As Integer = Val(strIndex.Chars(2))
            Call StoreMove(intX, intY, chrPlayer, chrTTT)
            If IsWinner(chrTTT) Then
                MessageBox.Show("Game over!")
            Else

                If chrPlayer = "X" Then
                    chrPlayer = "O"
                Else
                    chrPlayer = "X"
                End If
            End If
        End If
    End Sub

    Sub StoreMove(ByVal intX As Integer, ByVal intY As Integer, _
    ByVal chrPlayer As Char, ByRef chrTTT(,) As Char)
        chrTTT(intX, intY) = chrPlayer
    End Sub
    Function IsWinner(ByRef chrTTT(,) As Char) As Boolean
        Dim intRow As Integer
        For intRow = 0 To 2
            If chrTTT(intRow, 0) = chrTTT(intRow, 1) And _
            chrTTT(intRow, 1) = chrTTT(intRow, 2) And _
            (chrTTT(intRow, 0) = "X" Or chrTTT(intRow, 0) = "O") Then
                Return True ' You win!
            End If
        Next intRow

        Dim intCol As Integer
        For intCol = 0 To 2
            If chrTTT(0, intCol) = chrTTT(1, intCol) And _
            chrTTT(1, intCol) = chrTTT(2, intCol) And _
            (chrTTT(0, intCol) = "X" Or chrTTT(0, intCol) = "O") Then
                Return True ' Winner
            End If
        Next intCol

        If chrTTT(0, 0) = chrTTT(1, 1) And chrTTT(1, 1) = chrTTT(2, 2) _
        And (chrTTT(0, 0) = "X" Or chrTTT(0, 0) = "O") Then
            Return True ' Winner again!
        End If

        If chrTTT(0, 2) = chrTTT(1, 1) And chrTTT(1, 1) = chrTTT(2, 0) _
        And (chrTTT(0, 2) = "X" Or chrTTT(0, 2) = "O") Then
            Return True 'win
        End If

        Dim blnMovesLeft As Boolean = False
        For intRow = 0 To 2
            For intCol = 0 To 2
                If chrTTT(intRow, intCol) = Nothing Then
                    blnMovesLeft = True
                End If
            Next intCol
        Next intRow
        If Not blnMovesLeft Then
            Return True 'Squares filled!
        End If

        Return False ' Game goes on; no winner yet!
    End Function
End Class