Lotto Game

• Download source and demo - 256.11 KB

Introduction

Do you have a lottery habit?, If so, that is good, for me. This is a take off of the "Georgia State Lottery Mega Millions". It has tumbling animation for the five white balls and the same for the mega ball. It's free and won't break your wallet. It displays, in a DataGridView, all the winning numbers from the beginning of the year to date. I suppose you could use this to query the most called numbers for a slight advantage into the game.

Background

I've seen all sorts of lottery programs but none with tumbling animation, at least I haven't so far. The only one I did see was a VB 5 example and I did use and upgrade the class file that was used for the VB5 version. I do not know who the author is as the example was printed and is three days older than dirt, but I still have it.

The Animation

The animation takes place in two different events. The tumbleTimer_Tick event and the pnlTumble_Paint event. I originally was going to use a PictureBox control for the animation but was schooled in why not to use it and was pointed in the direction of the Panel control. The PictureBox is for showing images. That is it. The PictureBox has extra baggage that we do not need. The code for the tumbleTimer_Tick and the pnlTumble_Paint events are very straightforward and we do follow the "Windows Event Driven Rules".

Private Sub tumbleTimer_Tick(sender As Object, _
        e As System.EventArgs) Handles tumbleTimer.Tick
    _showGraphic = True
    pnlTumble.Invalidate()
End Sub

We simply set a Boolean to True and Invalidate the Panel that we are using for the animation. The Paint Event is where the meat of the animation takes place. Inside the Panel, we draw a rectangle that holds the circle and the centered text. We do this 56 times. We clear the Panel by painting everything black, dispose of the graphics, and start over again.

Private Sub pnlTumble_Paint(sender As Object, _
        e As System.Windows.Forms.PaintEventArgs) Handles pnlTumble.Paint

    Dim i As Integer = 0
    Dim xPos As Integer
    Dim yPos As Integer
    Dim rr As New Random
    Dim rect As New Rectangle

    For i = 1 To 56
        xPos = rr.Next(1, 300)
        yPos = rr.Next(1, 400)

        rect.Height = 50
        rect.Width = 50
        rect.Location = New Point(xPos, yPos)

        e.Graphics.FillEllipse(Brushes.White, rect.X, rect.Y, 50, 50)

        Dim f As Font = New Font("Arial", 12, FontStyle.Bold)
        Dim StringSize As SizeF = e.Graphics.MeasureString(i.ToString(), f)

        e.Graphics.DrawString(i.ToString(), f, Brushes.Black, _
           (rect.Left + 25) - (StringSize.Width / 2), _
           (rect.Top + 25) - (StringSize.Height / 2))
    Next
    e.Graphics.Clear(Color.Black)
    e.Graphics.Dispose()
End Sub

Clicking for a Ball

When you click to get the first ball, you would think that it is coming from the tumbling animation, but in all actuality, the animation is just a facade (pronounced "f·säd") for what is actually going on. In the btnNextBall_Click event, we first get the current count of selected balls; if all the balls are grabbed, then we start over, then we select the next unique ping-pong ball GrabNext(PPBalls), then we do some UI cosmetics.

GrabNext(PPBalls) is where we get random numbers for our ping-pong balls. The class clsRandom has just two properties, three subs, and six variables. The properties are...

• Random
• Randomint

The Subs are...

• Shuffle(dX As Double)
• Zap()
• Stir(dX As Double)

The variables are...

• Const SIZE
• MinInt Integer
• MaxInt Integer
• BJP(SIZE - 1) Double
• RSP Integer
• PJP Integer

The Shuffle sub is called in the Form_Load event which calls the Zap sub and the Stir sub. The code for the btnNextBall_Click event and the GrabNext(ByVal Ary()) sub follows...

Private Sub btnNextBall_Click(sender As Object, _
        e As System.EventArgs) Handles btnNextBall.Click
    If btnNextBall.Text = "Re-Start" Then
        btnNextBall.Text = "Next Ball"
        tumbleTimer.Start()
    End If

    Dim i As Integer
    i = PPBalls(0)

    If i = 5 Then
        For i = 0 To 5
            PPBalls(i) = 0
        Next
        Exit Sub
    End If

    GrabNext(PPBalls)

    If PPBalls(0) = 5 Then
        btnNextBall.Text = "Re-Start"
        tumbleTimer.Stop()
        pnlTumble.Hide()
        pnlMegaTumbler.Show()
        tumbleMegaTimer.Start()

        btnNextBall.Location = New Point(593, 546)
        btnNextBall.Enabled = False
        btnNextBall.Visible = False

        btnMegaBall.Location = New Point(594, 547)
        btnMegaBall.Enabled = True
        btnMegaBall.Visible = True
    End If
End Sub

Private Sub GrabNext(ByVal Ary())
    Dim i As Integer
    Dim j As Integer = 0

    Ary(0) = Ary(0) + 1
    i = Ary(0)

    Do
        Ary(i) = r.Randomint

        DisplayBall(Ary(i))

        If i > 1 Then
            For j = 1 To (i - 1)
                If Ary(i) = Ary(j) Then
                    Ary(i) = 0
                End If
            Next
        End If
    Loop Until Ary(i)

End Sub

I was going to get off track and write a little about "Windows Event Driven Rules" but after doing some searching on the subject, I found that this is another article in itself. So I'll stick to the "Windows Event Driven" subs that follow.

The DisplayBall() sub is a long-dragged-out If, ElseIf, End If statement. We call the Panel.Invalidate() command, which in turn calls the Panel.Paint event. This follows the Windows Event Driven Rules. More on this subject can be found on Wikipedia or by doing a Google Search which displays quite a few links on the subject.

Private Sub DisplayBall(ByVal ii As Integer)
    myBall = Nothing 'Exception Prevention.
    If ii = 1 Then
        myBall = 1
        _showGraphic = True
        Me.pnl1.Invalidate()
    ElseIf ii = 2 Then
        myBall = 2
        _showGraphic = True
        Me.pnl2.Invalidate()

        'Code Continues...
        '...
        '...
        '...
        
    ElseIf ii = 55 Then
        myBall = 55
        _showGraphic = True
        Me.pnl55.Invalidate()
    ElseIf ii = 56 Then
        myBall = 56
        _showGraphic = True
        Me.pnl56.Invalidate()
    End If

Private Sub pnl1_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) _
        Handles pnl1.Paint, pnl2.Paint, pnl3.Paint, pnl4.Paint, pnl5.Paint, _
        pnl6.Paint, pnl7.Paint, pnl8.Paint, pnl9.Paint, _
        pnl10.Paint, pnl11.Paint, pnl12.Paint, pnl13.Paint, _
        pnl14.Paint, pnl15.Paint, pnl16.Paint, pnl17.Paint, _
        pnl18.Paint, pnl19.Paint, pnl20.Paint, pnl21.Paint, _
        pnl22.Paint, pnl23.Paint, pnl24.Paint, pnl25.Paint, _
        pnl26.Paint, pnl27.Paint, pnl28.Paint, pnl29.Paint, _
        pnl30.Paint, pnl31.Paint, pnl32.Paint, pnl33.Paint, _
        pnl34.Paint, pnl35.Paint, pnl36.Paint, pnl37.Paint, _
        pnl38.Paint, pnl39.Paint, pnl40.Paint, pnl41.Paint, _
        pnl42.Paint, pnl43.Paint, pnl44.Paint, pnl45.Paint, _
        pnl46.Paint, pnl47.Paint, pnl48.Paint, pnl49.Paint, _
        pnl50.Paint, pnl51.Paint, pnl52.Paint, pnl53.Paint, _
        pnl54.Paint, pnl55.Paint, pnl56.Paint

    If _showGraphic Then
        Dim rect As New Rectangle
        rect.Height = 40
        rect.Width = 40
        rect.Location = New Point(0, 0)

        e.Graphics.FillEllipse(Brushes.White, rect.X, rect.Y, 40, 40)
        'Dim t As String = myBall.ToString()
        Dim f As Font = New Font("Arial", 10, FontStyle.Bold)
        Dim StringSize As SizeF = e.Graphics.MeasureString(myBall.ToString(), f)
        e.Graphics.DrawString(myBall.ToString(), f, Brushes.Black, _
          (rect.Left + 20) - (StringSize.Width / 2), _
          (rect.Top + 20) - (StringSize.Height / 2))
        e.Graphics.Dispose()

    End If
End Sub

The MegaBall subs are pretty much the same as the white ball subs displayed above, except on a smaller scale as we are calling only one ball.

If there is anything in this article that sounds somewhat redundant, it probably is, so please do not leave a message stating this as I already know.