Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles CheckBox1.CheckedChanged
        pb.Invalidate()
    End Sub
 
    Private Sub DoPaint(ByVal sender As System.Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles pb.Paint
        If Not CheckBox1.Checked Then Return
        Dim g As Graphics = e.Graphics
 
        Dim X1 As Integer
        Dim X2 As Integer
        Dim Y1 As Integer
        Dim Y2 As Integer
 
        Dim Farbe As New System.Drawing.Pen(Color.Red)
        Dim i As Integer
        X1 = 5
        Y1 = 48
        X2 = 10
        Y2 = 48
 
        For Y2 = 48 To 498 Step 50
            Y1 = Y2
            X1 = 5
            X2 = 10
            For i = 1 To 100
                g.DrawLine(Farbe, X1, Y1, X2, Y2)
                X1 = X2 + 5
                X2 = X2 + 10
            Next
        Next
        X1 = 133
        Y1 = 5
        X2 = 133
        Y2 = 10
        For X2 = 133 To 800 Step 133
            X1 = X2
            Y1 = 5
            Y2 = 10
            For i = 1 To 100
                g.DrawLine(Farbe, X1, Y1, X2, Y2)
                Y1 = Y2 + 5
                Y2 = Y2 + 10
            Next
        Next
 
    End Sub