VB.Net - Worker Thread / Invoking Example With Thread Start Stop

I wrote this to help me understand threading, hope it helps someone else.

Dave

Code:

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Option Explicit On
Option Strict On
Imports System.Threading

'  **********************************************************************************************
'  *  Created In VS2005                                                                        *
'  *  Example of multi or worker threading in VB.Net with start & stop of the worker thread    *
'  *  With invoking to update progress bar & textbox                                            *
'  *  Create a form with 2x buttons and 1x textbox & 1 x progress bar                          *
'  *  Modified from the MicroSoft Help So it actually works!!                                  *
'  **********************************************************************************************

Public Class Form1
    Dim WorkerThread As Thread                  'Create the worker thread
    Dim NewVal As Integer                      'New Value of progress bar & textbox
    Dim StopThread As Boolean = True            'Boolean Value used to halt the endless loop

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If StopThread = False Then
            StopThread = True
        Else
            StopThread = False
            WorkerThread = New Thread(AddressOf ThreadTask)
            WorkerThread.IsBackground = True
            WorkerThread.Start()
        End If
    End Sub

    Private Sub ThreadTask()
        Dim ProgBarStep As Integer
        Dim RandomNo As New Random()
        Do Until StopThread = True
            ProgBarStep = ProgressBar1.Step * RandomNo.Next(-1, 2)
            NewVal = ProgressBar1.Value + ProgBarStep
            If NewVal > ProgressBar1.Maximum Then
                NewVal = ProgressBar1.Maximum
            ElseIf NewVal < ProgressBar1.Minimum Then
                NewVal = ProgressBar1.Minimum
            End If
            Me.ProgressBar1.Invoke(New MethodInvoker(AddressOf InvokeProgBar1))
            Me.ProgressBar1.Invoke(New MethodInvoker(AddressOf InvokeTextBox1))
            Thread.Sleep(100)
        Loop
    End Sub

    Private Sub InvokeProgBar1()
        Me.ProgressBar1.Value = CInt(NewVal)
    End Sub

    Private Sub InvokeTextBox1()
        Me.TextBox1.Text = CStr(NewVal)
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        MessageBox.Show("This is the main thread")
    End Sub
End Class

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