Visual Basic

Imports System.Threading

Public Class BallClass

    Private colorValue As Color
    Private radiusValue As Single

    Private xValue As Single
    Private yValue As Single

    Private dxValue As Single 'x velocity
    Private dyValue As Single 'y velocity

    Private panelWidthValue As Integer
    Private panelHeightValue As Integer


    Public Sub New(ByVal BallColor As Color, ByVal BallRadius As Single, _
        ByVal BallXValue As Single, ByVal BallYValue As Single, _
        ByVal BalldX As Single, ByVal BalldY As Single, _
        ByVal BallPanelWidth As Integer, ByVal BallPanelHeight As Integer)

        Colour = BallColor
        Radius = BallRadius
        xValue = BallXValue
        yValue = BallYValue
        dX = BalldX
        dY = BalldY
        PanelWidth = BallPanelWidth
        PanelHeight = BallPanelHeight

    End Sub

    Public Property Colour() As Color
        Get
            Return colorValue
        End Get
        Set(ByVal value As Color)
            colorValue = value
        End Set
    End Property

    Public Property Radius() As Single
        Get
            Return radiusValue
        End Get
        Set(ByVal value As Single)
            radiusValue = value
        End Set
    End Property

    Public Property dX() As Single
        Get
            Return dxValue
        End Get
        Set(ByVal value As Single)
            dxValue = value
        End Set
    End Property

    Public Property dY() As Single
        Get
            Return dyValue
        End Get
        Set(ByVal value As Single)
            dyValue = value
        End Set
    End Property

    Public ReadOnly Property X() As Single
        Get
            Return xValue
        End Get
    End Property

    Public ReadOnly Property Y() As Single
        Get
            Return yValue
        End Get
    End Property

    Public Property PanelWidth() As Integer
        Get
            Return panelWidthValue
        End Get
        Set(ByVal value As Integer)
            panelWidthValue = value
        End Set
    End Property

    Public Property PanelHeight() As Integer
        Get
            Return panelHeightValue
        End Get
        Set(ByVal value As Integer)
            panelHeightValue = value
        End Set
    End Property

    Public Sub Run() 'makes ball move

        While True
            Thread.Sleep(10)
            If (xValue + Radius >= PanelWidth) Or xValue = 0 Then
                dX = -dX
            End If
            xValue += dX
        End While

    End Sub
End Class


Imports System.Threading

Public Class ballForm

    Private ball As BallClass

    Delegate Sub ReDelegate()

    Private Sub FrmBallTest_MouseClick(ByVal sender As System.Object, _
        ByVal e As System.Windows.Forms.MouseEventArgs) _
        Handles BallPanel.MouseClick

        'colour, radius, x, y, x-velociy, y-velocity, panel width, panel height
        ball = New BallClass(Color.Blue, 15, e.X, e.Y, 1, 1, BallPanel.Width, BallPanel.Height)

        Dim drawThread As New Thread(New ThreadStart(AddressOf Me.Draw))
        drawThread.Start()

        Dim runThread As New Thread(New ThreadStart(AddressOf ball.Run))
        runThread.Start()


    End Sub


    Private Sub FrmBallTest_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) _
        Handles MyBase.Load

        BallPanel.Width = 200
        BallPanel.Height = 200

    End Sub

    Private Sub FrmGUIThreads_FormClosing(ByVal sender As System.Object, _
        ByVal e As System.Windows.Forms.FormClosingEventArgs) _
        Handles MyBase.FormClosing

        System.Environment.Exit(System.Environment.ExitCode)

    End Sub
    Private Sub Draw() 'draws ball every 20 ms

        While True

            Thread.Sleep(5)

            Dim b As Graphics = BallPanel.CreateGraphics()
            b.FillEllipse(New SolidBrush(ball.Colour), ball.X, ball.Y, _
                ball.Radius, ball.Radius)
            b.Dispose()
            BallPanel.Invoke(New ReDelegate(AddressOf BallPanel.Refresh))
        End While

    End Sub


End Class