How Can I Do Multithreading better VB.net 4.7 framework?

Question

My Form1 freeze when using too many proxy threads after like 20sec it unfreeze but sometimes it freeze and I have to stop the solution.

My application use proxies and go to google and scrape images, keywords or emails ....so I have 4 options to scrape all are Public sub because I don't know how to do it other way.

What I try to do is Task Async method which could help not freeze even if I lunch 300 threads.

My code:

Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
    Try
            If chkManualProxies.Checked = True Then
                If lstProxies.Items.Count < 0 Then
                    MessageBox.Show("Please upload manual proxies OR uncheck 'Manual proxies'")
                    stop_process2()
                    Return
                End If
                disableOnStart()
            Else
                btnScrapeStart()
                disableOnStart()
            End If

            If chk_refresh_proxies.Checked Then
                countdown = CInt(num_refresh.Value)
                timer_countdown.Enabled = True
                Me.Timer1.Interval = CInt(Me.num_refresh.Value) * 1000
                Me.Timer1.Enabled = True
                disableOnStart()
            End If

            Timer1.Enabled = True
            ' scrape_on_Start()
            If rb_http.Checked Then _proxyType = 1
            If Me.rb_socks4.Checked Then _proxyType = 2
            If Me.rb_socks5.Checked Then _proxyType = 3

            _proxies.Clear()

            For Each item As ListViewItem In lstProxies.Items
                _proxies.Add(item.SubItems(0).Text + ":" + item.SubItems(1).Text)
            Next

            Dim num As Integer
            num = txtThreads.Value
            ThreadPool.SetMinThreads(num, num)
            _Count = 0
            _proxycount = lblProxies.Text.Count.ToString
            _runningThreads.Clear()

            Try


                
                Dim i As Integer
                For i = 0 To num - 1
                    If rb1.Checked = True Then
                        ComboBox1N.Enabled = True

                        Select Case ComboBox1N.SelectedIndex
                            Case 0
                                Try
                                    Dim t1 As Thread = New Thread(New ThreadStart(AddressOf TaskSub1)) 
                                    t1.Priority = Threading.ThreadPriority.Normal
                                    _runningThreads.Add(t1)
                                    t1.Start()
                                Catch ex As Exception
                                    MessageBox.Show(ex.Message)
                                End Try

                            Case 1
                                Try
                                    Dim t2 As Thread = New Thread(New ThreadStart(AddressOf TaskSub2))
                                    t2.Priority = Threading.ThreadPriority.Normal
                                    _runningThreads.Add(t2)
                                    t2.Start()
                                Catch ex As Exception
                                    MessageBox.Show(ex.Message)
                                End Try                              

                        End Select

                    Else
                        ComboBox1N.Enabled = True
                        Select Case ComboBox1N.SelectedIndex

                                Try
                                    getInfo()
                                    Dim t3 As Thread = New Thread(New ThreadStart(AddressOf TaskSub3))
                                    t3.Priority = Threading.ThreadPriority.Normal
                                    _runningThreads.Add(t3)
                                    t3.Start()
                                Catch ex As Exception
                                    MessageBox.Show(ex.Message)
                                End Try

                            Case 3
                                Try
                                    getInfo()
                                    Dim t4 As Thread = New Thread(New ThreadStart(AddressOf TaskSub4))
                                    t4.Priority = Threading.ThreadPriority.Normal
                                    _runningThreads.Add(t4)
                                    t4.Start()
                                Catch ex As Exception
                                    MessageBox.Show(ex.Message)
                                End Try

                        End Select

                    End If

                Next


            Catch ex As Exception
                 MessageBox.Show(ex.Message)
            End Try

    Catch ex As Exception
         MessageBox.Show(ex.Message)
    End Try

End Sub

Thanks for any suggestion I know my code need to many changes but I would like to know what should I start to change as first and what is wrong coding, sorry I learned myself from Lynda. com and youtube.

Answer 1

等待大神答复