Visual Basic - Issue with how the code is being Executed - vb.net

Question

So I have a button that Scrapes Proxies from Public Websites and adds the proxies to a Listbox but there's an issue, It for some reason shows the Proxies in the Listbox once its Actually finished doing all the "For Each"'s.
It even doesn't show a Progress Bar until everything is Finished which is making it pointless.
Screenshot of what I mean:
(As you can see it only shows the Progress Bar when its finished rather then while its Scraping.)
Is there any workaround for this?
My Code:
Imports System.Text.RegularExpressions
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Button1.Enabled = False
ScrapeProgress.Visible = True
'Set the Time;
Dim time = TimeOfDay.ToString("h:mm:ss tt")
'Sources;
Dim sources(122) As String
sources(0) = "http://proxy-ip-list.com"
sources(1) = "http://fineproxy.org/eng/?p=6#more-6"
sources(2) = "http://aliveproxy.com/high-anonymity-proxy-list"
sources(3) = "http://aliveproxy.com/anonymous-proxy-list/"
sources(4) = "http://aliveproxy.com/transparent-proxy-list"
sources(5) = "http://aliveproxy.com/socks5-list"
sources(6) = "http://aliveproxy.com/socks4-list"
sources(7) = "http://aliveproxy.com/fastest-proxies/"
sources(8) = "http://atomintersoft.com/anonymous_proxy_list"
sources(9) = "http://atomintersoft.com/high_anonymity_elite_proxy_list"
sources(10) = "http://atomintersoft.com/proxy_list_domain"
sources(11) = "http://atomintersoft.com/proxy_list_port"
sources(12) = "http://atomintersoft.com/transparent_proxy_list"
sources(13) = "http://atomintersoft.com/products/alive-proxy/socks5-list"
sources(14) = "http://best-proxy.com/english/search.php?search=anonymous-and-elite&country=any&type=anonymous-and-elite&port=any&ssl=any"
sources(15) = "http://best-proxy.com/english/search.php?search=anonymous-and-elite&country=any&type=anonymous-and-elite&port=any&ssl=any&p=2"
sources(16) = "http://best-proxy.com/english/search.php?search=anonymous-and-elite&country=any&type=anonymous-and-elite&port=any&ssl=any&p=3"
sources(17) = "http://www.samair.ru/proxy/socks01.htm"
sources(18) = "http://www.samair.ru/proxy/socks02.htm"
sources(19) = "http://www.samair.ru/proxy/socks03.htm"
sources(20) = "http://www.samair.ru/proxy/socks04.htm"
sources(21) = "http://www.samair.ru/proxy/socks05.htm"
sources(22) = "http://www.samair.ru/proxy/proxy-01.htm"
sources(23) = "http://www.samair.ru/proxy/proxy-02.htm"
sources(24) = "http://www.samair.ru/proxy/proxy-03.htm"
sources(25) = "http://www.samair.ru/proxy/proxy-04.htm"
sources(26) = "http://www.samair.ru/proxy/proxy-05.htm"
sources(27) = "http://www.samair.ru/proxy/proxy-06.htm"
sources(28) = "http://www.samair.ru/proxy/proxy-07.htm"
sources(29) = "http://www.samair.ru/proxy/proxy-08.htm"
sources(30) = "http://www.samair.ru/proxy/proxy-09.htm"
sources(31) = "http://www.samair.ru/proxy/proxy-10.htm"
sources(32) = "http://www.samair.ru/proxy/proxy-11.htm"
sources(33) = "http://www.samair.ru/proxy/proxy-12.htm"
sources(34) = "http://www.samair.ru/proxy/proxy-13.htm"
sources(35) = "http://www.samair.ru/proxy/proxy-14.htm"
sources(36) = "http://www.samair.ru/proxy/proxy-15.htm"
sources(37) = "http://www.samair.ru/proxy/proxy-16.htm"
sources(38) = "http://www.samair.ru/proxy/proxy-17.htm"
sources(39) = "http://www.samair.ru/proxy/proxy-18.htm"
sources(40) = "http://www.samair.ru/proxy/proxy-19.htm"
sources(41) = "http://www.samair.ru/proxy/proxy-20.htm"
sources(42) = "http://www.samair.ru/proxy/proxy-21.htm"
sources(43) = "http://www.samair.ru/proxy/proxy-22.htm"
sources(44) = "http://www.samair.ru/proxy/proxy-23.htm"
sources(45) = "http://www.samair.ru/proxy/proxy-24.htm"
sources(46) = "http://www.samair.ru/proxy/proxy-25.htm"
sources(47) = "http://www.samair.ru/proxy/proxy-26.htm"
sources(48) = "http://www.samair.ru/proxy/proxy-27.htm"
sources(49) = "http://www.samair.ru/proxy/proxy-28.htm"
sources(50) = "http://www.samair.ru/proxy/proxy-29.htm"
sources(51) = "http://www.samair.ru/proxy/proxy-30.htm"
sources(52) = "http://nntime.com/proxy-list-01.htm"
sources(53) = "http://nntime.com/proxy-list-02.htm"
sources(54) = "http://nntime.com/proxy-list-03.htm"
sources(55) = "http://nntime.com/proxy-list-04.htm"
sources(56) = "http://nntime.com/proxy-list-05.htm"
sources(57) = "http://nntime.com/proxy-list-06.htm"
sources(58) = "http://nntime.com/proxy-list-07.htm"
sources(59) = "http://nntime.com/proxy-list-08.htm"
sources(60) = "http://nntime.com/proxy-list-09.htm"
sources(61) = "http://nntime.com/proxy-list-10.htm"
sources(62) = "http://nntime.com/proxy-list-11.htm"
sources(63) = "http://nntime.com/proxy-list-12.htm"
sources(64) = "http://nntime.com/proxy-list-13.htm"
sources(65) = "http://nntime.com/proxy-list-14.htm"
sources(66) = "http://nntime.com/proxy-list-15.htm"
sources(67) = "http://nntime.com/proxy-list-16.htm"
sources(68) = "http://nntime.com/proxy-list-17.htm"
sources(69) = "http://nntime.com/proxy-list-18.htm"
sources(70) = "http://nntime.com/proxy-list-19.htm"
sources(71) = "http://nntime.com/proxy-list-20.htm"
sources(72) = "http://nntime.com/proxy-list-21.htm"
sources(73) = "http://nntime.com/proxy-list-22.htm"
sources(74) = "http://nntime.com/proxy-list-23.htm"
sources(75) = "http://nntime.com/proxy-list-24.htm"
sources(76) = "http://nntime.com/proxy-list-25.htm"
sources(77) = "http://nntime.com/proxy-list-26.htm"
sources(78) = "http://nntime.com/proxy-list-27.htm"
sources(79) = "http://nntime.com/proxy-list-28.htm"
sources(80) = "http://nntime.com/proxy-list-29.htm"
sources(81) = "http://nntime.com/proxy-list-30.htm"
sources(82) = "http://proxylistchecker.org/proxylists.php?t=&p=1"
sources(83) = "http://proxylistchecker.org/proxylists.php?t=&p=2"
sources(84) = "http://proxylistchecker.org/proxylists.php?t=&p=3"
sources(85) = "http://proxylistchecker.org/proxylists.php?t=&p=4"
sources(86) = "http://proxylistchecker.org/proxylists.php?t=&p=5"
sources(87) = "http://proxylistchecker.org/proxylists.php?t=&p=6"
sources(88) = "http://proxylistchecker.org/proxylists.php?t=&p=7"
sources(89) = "http://proxylistchecker.org/proxylists.php?t=&p=8"
sources(90) = "http://proxylistchecker.org/proxylists.php?t=&p=9"
sources(91) = "http://proxylistchecker.org/proxylists.php?t=&p=10"
sources(92) = "http://proxylistchecker.org/proxylists.php?t=&p=11"
sources(93) = "http://proxylistchecker.org/proxylists.php?t=&p=12"
sources(94) = "http://proxylistchecker.org/proxylists.php?t=&p=13"
sources(95) = "http://proxylistchecker.org/proxylists.php?t=&p=14"
sources(96) = "http://proxylistchecker.org/proxylists.php?t=&p=15"
sources(97) = "http://txt.proxyspy.net/proxy.txt"
sources(98) = "http://www.getproxy.jp/en/default/1"
sources(99) = "http://www.getproxy.jp/en/default/2"
sources(100) = "http://www.getproxy.jp/en/default/3"
sources(101) = "http://www.getproxy.jp/en/default/4"
sources(102) = "http://www.getproxy.jp/en/default/5"
sources(103) = "http://www.ip-adress.com/proxy_list/?k=time&d=desc"
sources(104) = "http://www.my-proxy.com/free-proxy-list.html"
sources(105) = "http://www.my-proxy.com/free-proxy-list-2.html"
sources(106) = "http://www.my-proxy.com/free-proxy-list-3.html"
sources(107) = "http://www.my-proxy.com/free-proxy-list-4.html"
sources(108) = "http://www.my-proxy.com/free-proxy-list-5.html"
sources(109) = "http://www.my-proxy.com/free-proxy-list-6.html"
sources(110) = "http://www.my-proxy.com/free-proxy-list-7.html"
sources(111) = "http://www.my-proxy.com/free-proxy-list-8.html"
sources(112) = "http://www.my-proxy.com/free-proxy-list-9.html"
sources(113) = "http://www.my-proxy.com/free-proxy-list-10.html"
sources(114) = "http://sslproxies24.blogspot.com/feeds/posts/default"
sources(115) = "http://proxyserverlist-24.blogspot.com/feeds/posts/default"
sources(116) = "http://newfreshproxies24.blogspot.com/feeds/posts/default"
sources(117) = "http://socksproxylist24.blogspot.com/feeds/posts/default"
sources(118) = "http://vip-socks24.blogspot.com/feeds/posts/default"
sources(119) = "http://irc-proxies24.blogspot.com/feeds/posts/default"
sources(120) = "http://www.socks24.org/feeds/posts/default"
sources(121) = "http://www.getproxy.jp/en/"
sources(122) = "http://www.getproxy.jp/en/fastest"
'Add the Copyright Holder to the top of the List;
ListBox1.Items.Add("Proxies Scraped using a Test Build Program by ShinyMK")
'Foreach Source, Do the following Code;
For Each element As String In sources
'Set the Status Label to "Scraping";
ToolStripStatusLabel3.Text = "Scraping"
'Connect to the Proxy Source;
Dim source As Net.HttpWebRequest = Net.WebRequest.Create(element)
Try
'Prepare the Response;
Dim response As Net.HttpWebResponse = source.GetResponse
'Load the HTML;
Dim reader As IO.StreamReader = New IO.StreamReader(response.GetResponseStream())
Dim html As String = reader.ReadToEnd
'Regex;
Dim expression As New Regex("[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}:[0-9]{1,4}")
'Set the Matches variable to the Matched Sections of the HTML source;
Dim matches As MatchCollection = expression.Matches(html)
'Add the proxies to the ListBox;
For Each proxy As Match In matches
'If the ListBox doesn't already contain the Proxy, Add It;
If Not ListBox1.Items.Contains(proxy.ToString) Then
'Add the Proxy;
ListBox1.Items.Add(proxy.ToString)
'Add 1 to the "Count" label's value;
ToolStripStatusLabel5.Text += 1
End If
Next
'Add the Time and Success message for each Successful Scraped Source;
ListBox2.Items.Add("[" + time + "] Success: " + element)
Catch ex As Exception
ListBox2.Items.Add("[" + time + "] ERROR Scraping from " + element + " - " + ex.Message)
End Try
Next
'Re-Enable the Button and set the Status Lable to "Idle";
Button1.Enabled = True
ToolStripStatusLabel3.Text = "Idle"
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
If ListBox1.Items.Count = (0) Then
MessageBox.Show("No Proxies Scraped.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Else
'defining a streamwriter
Dim S_W As IO.StreamWriter
'converting listbox items to string
Dim itms() As String = {ListBox1.Items.ToString}
''defining a savefiledialog
Dim save As New SaveFileDialog
Dim it As Integer
save.FileName = "SSLPro.xyz " + TimeOfDay.ToString("h.mm.ss tt")
save.Filter = "Text (*.txt)|*.txt|All Files (*.*)|*.*"
save.CheckPathExists = True
save.ShowDialog(Me)
S_W = New IO.StreamWriter(save.FileName)
For it = 0 To ListBox1.Items.Count - 1
S_W.WriteLine(ListBox1.Items.Item(it))
Next
S_W.Close()
End If
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
ListBox1.Items.Clear()
ListBox2.Items.Clear()
ToolStripStatusLabel5.Text = "0"
End Sub
End Class

Answer 1

To allow your UI thread to refresh and show the information while you’re iterating through the proxies you need to use a separate thread to do the job.
You can use the .NET control Backgroundworker to do this. With this control you can start a thread to do the job and this thread can inform the UI thread of the state of the operation using the events of the Brackgroundworker, then the UI thread can update the UI accordingly.
Here you can find some examples of how to use a backgroundworker.
A basic sample of this could be something like:
Imports System.ComponentModel
Public Class Form1
Private ListOfProcessedElements as List(of integer)
Private Sub backgroundWorker1_DoWork(ByVal sender As System.Object,ByVal e As DoWorkEventArgs) Handles backgroundWorker1.DoWork
'Here you do your worker
'Add an element to the list of Processed elements
ListOfProcessedElements.add(ANY_NUMBER)
worker.ReportProgress(i * 10)
End Sub
' This event handler updates the progress.
Private Sub backgroundWorker1_ProgressChanged(ByVal sender As System.Object, ByVal e As ProgressChangedEventArgs) Handles backgroundWorker1.ProgressChanged
'Here you can access to the shared variable ListOfProcessedElements and do whatever you want in the UI
End Sub
' This event handler deals with the results of the background operation.
Private Sub backgroundWorker1_RunWorkerCompleted(ByVal sender As System.Object, ByVal e As RunWorkerCompletedEventArgs) Handles backgroundWorker1.RunWorkerCompleted
End Sub
End Class