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Graphics porblem

bodeenbodeen Member Posts: 2
This simple sample works fine unless I try to draw a line.
The "real" program is based on using info from scrollbars to draw picutres.

Thanks for any suggestions.
Chuck Bodeen
*******************************************************************

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms

Public Class Form1
Inherits System.Windows.Forms.Form
' common variables
Friend v1, v2, v3, v4, counter As Integer
Dim ep As PaintEventArgs
Dim epen As Pen
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)

************************************************************************
any of the next 3 statements cause an error:
'"An unhandled exception of type
' System.NullReferenceException'
' occurred in system.windows.forms.dll
*************************************************************************
'epen.Color = System.Drawing.Color.Red
'epen.Width = 4
'e.Graphics.DrawLine(epen, 20, 100, 100, 100)
counter = counter + 1
TextBox3.Text = v1 + v2
TextBox4.Text = counter
End Sub
Private Sub VScrollBar1_Scroll(ByVal sender As Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles VScrollBar1.Scroll
v1 = VScrollBar1.Value
TextBox1.Text = v1
OnPaint(ep)
End Sub

Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
v2 = 2 * v1
TextBox2.Text = v2
OnPaint(ep)
'DrawLineFloat(ep)
End Sub


Chuck Bodeen
"Everybody comes to Las Vegas --- and usually stays with me!"
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