' RandomPoints Example

' Show how to use the DrawEllipse method
' to draw random points in the Paint method
' of a picture box.

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 picDisplay As System.Windows.Forms.PictureBox
    Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu
    Friend WithEvents mnuPoints As System.Windows.Forms.MenuItem
    Friend WithEvents mnu100 As System.Windows.Forms.MenuItem
    Friend WithEvents mnu1000 As System.Windows.Forms.MenuItem
    Friend WithEvents mnu10000 As System.Windows.Forms.MenuItem
    Friend WithEvents mnu100000 As System.Windows.Forms.MenuItem
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.picDisplay = New System.Windows.Forms.PictureBox
        Me.MainMenu1 = New System.Windows.Forms.MainMenu
        Me.mnuPoints = New System.Windows.Forms.MenuItem
        Me.mnu100 = New System.Windows.Forms.MenuItem
        Me.mnu1000 = New System.Windows.Forms.MenuItem
        Me.mnu10000 = New System.Windows.Forms.MenuItem
        Me.mnu100000 = New System.Windows.Forms.MenuItem
        Me.SuspendLayout()
        '
        'picDisplay
        '
        Me.picDisplay.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
        Me.picDisplay.Location = New System.Drawing.Point(48, 24)
        Me.picDisplay.Name = "picDisplay"
        Me.picDisplay.Size = New System.Drawing.Size(300, 300)
        Me.picDisplay.TabIndex = 0
        Me.picDisplay.TabStop = False
        '
        'MainMenu1
        '
        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnuPoints})
        '
        'mnuPoints
        '
        Me.mnuPoints.Index = 0
        Me.mnuPoints.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnu100, Me.mnu1000, Me.mnu10000, Me.mnu100000})
        Me.mnuPoints.Text = "Number of Points"
        '
        'mnu100
        '
        Me.mnu100.Index = 0
        Me.mnu100.Text = "100"
        '
        'mnu1000
        '
        Me.mnu1000.Index = 1
        Me.mnu1000.Text = "1000"
        '
        'mnu10000
        '
        Me.mnu10000.Index = 2
        Me.mnu10000.Text = "10000"
        '
        'mnu100000
        '
        Me.mnu100000.Index = 3
        Me.mnu100000.Text = "100000"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(392, 350)
        Me.Controls.Add(Me.picDisplay)
        Me.Menu = Me.MainMenu1
        Me.Name = "Form1"
        Me.Text = "RandomPoints"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Dim n As Integer = 100
    Dim rad As Integer = 4

    Private Sub picDisplay_Paint(ByVal sender As Object, _
        ByVal e As System.Windows.Forms.PaintEventArgs) _
        Handles picDisplay.Paint

        Dim i, x, y As Integer
        Dim r As New Random
        Dim b As New SolidBrush(Color.Red)

        Dim g As Graphics = e.Graphics
        For i = 1 To n
            x = r.Next(0, 300)
            y = r.Next(0, 300)
            g.FillEllipse(b, x - rad, y - rad, rad, rad)
        Next
    End Sub

    Private Sub mnu100_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu100.Click

        n = 100
        rad = 4
        picDisplay.Invalidate()
    End Sub

    Private Sub mnu1000_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu1000.Click

        n = 1000
        rad = 3
        picDisplay.Invalidate()
    End Sub

    Private Sub mnu10000_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu10000.Click

        n = 10000
        rad = 2
        picDisplay.Invalidate()
    End Sub

    Private Sub mnu100000_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu100000.Click

        n = 100000
        rad = 2
        picDisplay.Invalidate()
    End Sub
End Class