' RandomLines Example

' Use the Graphics context drawing methods to draw
' a picture with random lines in the Paint event handler.

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 mnuBrushes As System.Windows.Forms.MenuItem
    Friend WithEvents mnu1 As System.Windows.Forms.MenuItem
    Friend WithEvents mnu2 As System.Windows.Forms.MenuItem
    Friend WithEvents mnu5 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.mnuBrushes = New System.Windows.Forms.MenuItem
        Me.mnu1 = New System.Windows.Forms.MenuItem
        Me.mnu2 = New System.Windows.Forms.MenuItem
        Me.mnu5 = New System.Windows.Forms.MenuItem
        Me.SuspendLayout()
        '
        'picDisplay
        '
        Me.picDisplay.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
        Me.picDisplay.Location = New System.Drawing.Point(192, 88)
        Me.picDisplay.Name = "picDisplay"
        Me.picDisplay.Size = New System.Drawing.Size(80, 64)
        Me.picDisplay.TabIndex = 0
        Me.picDisplay.TabStop = False
        '
        'MainMenu1
        '
        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnuBrushes})
        '
        'mnuBrushes
        '
        Me.mnuBrushes.Index = 0
        Me.mnuBrushes.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnu1, Me.mnu2, Me.mnu5})
        Me.mnuBrushes.Text = "Number of Colors"
        '
        'mnu1
        '
        Me.mnu1.Index = 0
        Me.mnu1.Text = "1"
        '
        'mnu2
        '
        Me.mnu2.Index = 1
        Me.mnu2.Text = "2"
        '
        'mnu5
        '
        Me.mnu5.Index = 2
        Me.mnu5.Text = "5"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(328, 266)
        Me.Controls.Add(Me.picDisplay)
        Me.Menu = Me.MainMenu1
        Me.Name = "Form1"
        Me.Text = "RandomPoints Example"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Dim p() As Pen = New Pen() _
        {New Pen(Color.Black, 2), _
         New Pen(Color.White, 2), _
         New Pen(Color.Red, 2), _
         New Pen(Color.Lime, 2), _
         New Pen(Color.Blue, 2)}
    Dim nColors As Integer = 1
    Dim nLines As Integer = 200

    Private Sub ResizePictureBox()

        picDisplay.Location = New Point(0, 0)
        picDisplay.Size = Me.ClientSize
    End Sub
    Private Sub ResizePictureBox(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load, MyBase.Resize

        ResizePictureBox()
    End Sub

    Private Sub Form1_Resize(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles MyBase.Resize

        ResizePictureBox()
    End Sub

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

        Dim g As Graphics = e.Graphics
        Dim r As New Random
        Dim c, i, x1, y1, x2, y2 As Integer
        Dim w As Integer = picDisplay.Width
        Dim h As Integer = picDisplay.Height

        For i = 1 To nLines
            x1 = r.Next(0, w)
            y1 = r.Next(0, h)
            x2 = r.Next(0, w)
            y2 = r.Next(0, h)
            c = r.Next(0, nColors)
            g.DrawLine(p(c), x1, y1, x2, y2)
        Next
    End Sub

    Private Sub mnu1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu1.Click

        nColors = 1
        picDisplay.Invalidate()
    End Sub

    Private Sub mnu2_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu2.Click

        nColors = 2
        picDisplay.Invalidate()
    End Sub

    Private Sub mnu5_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles mnu5.Click

        nColors = 5
        picDisplay.Invalidate()
    End Sub
End Class